| 1 | 2099 A.D. Genesis | 1st appearance of Fantastic Four 2099; 1st appearance of X-Nation 2099; 1st Appearance of X-Nation 2099; 1st Appearance of X-Nation 2099 and Fantastic Four 2099 |
| 261 | Action Comics | 1st Appearance of Streaky the Supercat; 1st appearance of X-Kryptonite; Origin of Streaky the Supercat |
| 1-3 | Aliens vs. Avengers | 1st Appearance of Ahura Boltagon (Earth-TRN1414); 1st Appearance of Apocalypse (En Sabah Nur - Earth-TRN1414); 1st Appearance of Black Bolt (Blackagar Boltagon - Earth-TRN1414); 1st Appearance of Black Panther (Azari - Earth-TRN1414); 1st Appearance of Black Panther (T’Challa - Earth-TRN1414); 1st Appearance of Captain Marvel (Carol Danvers - Earth-TRN1414); 1st Appearance of Hatut Zeraze (Earth-TRN1414); 1ST Appearance of Hulk (Robert“Bruce”Banner - Earth-TRN1414); 1st Appearance of Lockjaw (Earth-TRN1414); 1st Appearance of Peter Wayland; 1st Appearance of Spider-Man (Miles Morales - Earth-TRN1414); 1st Appearance of Triton; 1st Appearance of Valeria Richards (Earth-TRN1414); 1st Appearance of Venom (Symbiote - Earth-TRN1414); 1st Appearance of Weyland Corporation; 1st Appearance of Xenomorphs XX121 (Aliens) |
| 2 | All-New Wolverine | 1st Appearance of Captain Mooney of Alchemax; 1st Appearance of Robert Chandler of Alchemax; 1st Appearance of X23_1BEL; 1st Appearance of X23_2ZEL; 1st Appearance of X23_4GAB (Gabby Kinney) |
| 2-2 | All-New Wolverine | 1st Appearance of Captain Mooney of Alchemax; 1st Appearance of Robert Chandler of Alchemax; 1st Appearance of X23_1BEL; 1st Appearance of X23_2ZEL; 1st Appearance of X23_4GAB (Gabby Kinney) |
| 2/A | All-New Wolverine | 1st Appearance of Captain Mooney of Alchemax; 1st Appearance of Robert Chandler of Alchemax; 1st Appearance of X23_1BEL; 1st Appearance of X23_2ZEL; 1st Appearance of X23_4GAB (Gabby Kinney) |
| Anl 2 | Amazing Spider-Man, The | Reprints Amazing Spider-Man #1, #2, and #5; 1st appearance of Xandu |
| 27 | Amazing Spider-Man, The (4th Series) | 1st appearance of Foxtrot (Wild Pack); 1st appearance of Juliet; 1st appearance of Romeo (Wild Pack); 1st appearance of Tango (Wild Pack); 1st appearance of X-Ray (Wild Pack); Return of the Wild Pack; Quitting of Mockingbird from S.H.I.E.L.D. |
| 15 | Amazing X-Men (2nd Series) | 1st Appearance of Xun |
| 1 | Custom: Deal—Fox Home Entertainment (X-3 Stan Lee DVD Comic) | Reprints X-Men (1st Series) # 1; Reprints X-Men (1st Series) # 4; Reprints X-Men (1st Series) # 9; 1st appearance of X-Men; 1st appearance of Angel; 1st appearance of Angel II; 1st appearance of Beast; 1st appearance of Cyclops; 1st appearance of Iceman; 1st appearance of Marvel Girl; 1st appearance of Professor X; 1st appearance of Magneto; 1st appearance of Brotherhood of Evil Mutants; 1st appearance of Mastermind; 1st appearance of Quicksilver; 1st appearance of Scarlet Witch; 1st appearance of Toad; 1st appearance of Lucifer; 96 pages; Digest-size |
| 1/NS | Custom: Deal—Fox Home Entertainment (X-3 Stan Lee DVD Comic) | Reprints X-Men (1st Series) # 1; Reprints X-Men (1st Series) # 4; Reprints X-Men (1st Series) # 9; 1st appearance of Angel; 1st appearance of Angel II; 1st appearance of Beast; 1st appearance of Brotherhood of Evil Mutants; 1st appearance of Cyclops; 1st appearance of Iceman; 1st appearance of Lucifer; 1st appearance of Magneto; 1st appearance of Marvel Girl; 1st appearance of Mastermind; 1st appearance of Professor X; 1st appearance of Quicksilver; 1st appearance of Scarlet Witch; 1st appearance of Toad; 1st appearance of X-Men; 96 pages; Digest-size |
| 8 | Dark Horse Comics | 1st appearance of X |
| 1 | Deathrow | 1st Appearance of X-187; Includes trading card; Adult; B&W |
| 179 | Doctor Strange (1st Series) | 1st appearance of Xandu; Don McGregor L.O.C. |
| 19 | Doctor Strange (2nd Series) | 1st appearance of Creators; 1st appearance of Xander; Doctor Strange stripped of Sorcerer Supreme title; Peter Sanderson L.O.C. |
| 1 | Doctor Strange (5th Series) | 1st Appearance of X’axal; 1st Appearance of the Gryndans |
| 18 | Doctor Strange (5th Series) | 1st Appearance of Butch (dog); 1st Appearance of Gene Stanton; 1st Appearance of Maddy Stanton; 1st Appearance of Mrs. Stanton; 1st Appearance of Xennerak |
| 1 | Doom 2099 | 1st appearance of Doom 2099 (Victor von Doom); 1st appearance of Wire (Wyatt); 1st appearance of Xandra; 1st appearance of Zefiro Clan; 1st appearance of Fortune; 1st appearance of Andreï; 1st appearance of Vox; 1st appearance of Tiger Wyld; 1st appearance of Zone |
| 1/NS | Doom 2099 | 1st appearance of Andreï; 1st appearance of Doom 2099 (Victor von Doom); 1st appearance of Fortune; 1st appearance of Tiger Wyld; 1st appearance of Vox; 1st appearance of Wire (Wyatt); 1st appearance of Xandra; 1st appearance of Zefiro Clan; 1st appearance of Zone |
| 1 | Fantastic Firsts | Reprints Fantastic Four #1; Reprints Tales to Astonish #27; Reprints Hulk #1; Reprints Amazing Fantasty #15; Reprints Journey into Mystery #83; Reprints Tales of Suspense #39 & 63; Reprints Sgt. Fury #1; Reprints Strange Tales #110; Reprints Avengers #1 & 4; Reprints X-Men #1; Reprints Silver Surfer #1; 1st appearance of Spider-Man; 1st appearance of the Hulk; 1st appearance of Ant-Man; 1st appearance of the Sub-Mariner; 1st appearance of Thor; 1st appearance of Iron Man; 1st appearance of Sgt. Fury; 1st appearance of Dr. Strange; 1st appearance of Avengers; 1st appearance of Captain America; 1st appearance of Daredevil; 1st appearance of S.H.I.E.L.D.; 1st appearance of Silver Surfer; 1st appearance of X-Men; 1st appearance of Fantastic Four; Fantastic Four Annual #1 |
| 1-2 | Fantastic Firsts | Reprints Fantastic Four #1; Reprints Tales to Astonish #27; Reprints Hulk #1; Reprints Amazing Fantasty #15; Reprints Journey into Mystery #83; Reprints Tales of Suspense #39 & 63; Reprints Sgt. Fury #1; Reprints Strange Tales #110; Reprints Avengers #1 & 4; Reprints X-Men #1; Reprints Silver Surfer #1; 1st appearance of Spider-Man; 1st appearance of the Hulk; 1st appearance of Ant-Man; 1st appearance of the Sub-Mariner; 1st appearance of Thor; 1st appearance of Iron Man; 1st appearance of Sgt. Fury; 1st appearance of Dr. Strange; 1st appearance of Avengers; 1st appearance of Captain America; 1st appearance of Daredevil; 1st appearance of S.H.I.E.L.D.; 1st appearance of Silver Surfer; 1st appearance of X-Men; 1st appearance of Fantastic Four; Origin of Wolverine; 115; 135; Fantastic Four Annual #1 |
| 1 | Giant-Size X-Men (Marvel Deutschland) | Reprints from X-Men (1st Series) #43; 1st Appearance of Illyana Rasputin; 1st Appearance of Nightcrawler; 1st Appearance of Storm; 1st Appearance of Thunderbird; 1st Appearance of X-Men (new); 1st Appearance of Colossus; 1st appearance of Nightcrawler (Kurt Wagner); 1st appearance of Storm (Ororo Munroe); 1st appearance of Thunderbird (John Proudstar); 1st appearance of Colossus (Peter Rasputin); 1st appearance of Illyana Rasputin; Origin of Storm; Origin of Storm (Ororo Munroe); Origin of Nightcrawler (Kurt Wagner); Origin of Nightcrawler; Summer 1975 |
| 1 | Gremlin Trouble | 1st Appearance of Cypher; 1st Appearance of Remi-el; 1st Appearance of Xynophylyen; The Chief Imp |
| 148 | Guardians of the Galaxy | 1st Appearance of Quinon; 1st Appearance of Xian |
| 136 | Incredible Hulk, The | 1st appearance of Xeron; 1st appearance of Klaatu |
| 254 | Incredible Hulk, The | 1st Appearance of Ironclad; 1st appearance of U-Foes; 1st appearance of Vector; 1st appearance of X-Ray; 1st Appearance of Vapor; Origin of U-Foes |
| 254/NS | Incredible Hulk, The | 1st Appearance of Ironclad; 1st appearance of U-Foes; 1st Appearance of Vapor; 1st appearance of Vector; 1st appearance of X-Ray; Origin of U-Foes |
| 136 | Incredible Hulk, The (UK Edition) | 1st appearance of Xeron; 1st appearance of Klaatu |
| 254 | Incredible Hulk, The (UK Edition) | 1st Appearance of Ironclad; 1st appearance of U-Foes; 1st appearance of Vector; 1st appearance of X-Ray; 1st Appearance of Vapor; Origin of U-Foes |
| 4 | Inhuman | 1st Appearance of Forey; 1st Appearance of Reader; 1st Appearance of Xiaoyi |
| 4/A | Inhuman | 1st Appearance of Forey; 1st Appearance of Reader; 1st Appearance of Xiaoyi |
| 595 | Invincible Iron Man | 1st Appearance of Xavier King |
| 62 | Journey into Mystery (1st Series) | 1st Appearance of Xemnu; Hulk try-out? |
| 62 | Journey into Mystery (UK Edition, 1st Series) | 1st Appearance of Xemnu; Hulk try-out? |
| 1 | League of Super Groovy Crimefighters | 1st Appearance of Atlas (crimefighter); 1st appearance of Black Belt; 1st appearance of Cupid; 1st appearance of Mr. Phenomenal; 1st appearance of The Ring; 1st appearance of Thor (Crimefighter); 1st appearance of X |
| 5 | Lost Universe (Gene Roddenberry’s…) | 1st Appearance of Xander |
| 7 | Magnus Robot Fighter (Valiant) | 1st appearance of X-O Armor; Versus Rai; Includes trading card; Includes coupon for #0 issue; Flipbook |
| 2 | Major X | 1st Appearance of X-Ential (Earth-TRN757); 1st Appearance of Catalyst (Earth-TRN757); 1st Appearance of Lora (Earth-TRN757); 1st Appearance of Namor (Earth-TRN757); 1st Appearance of Nomar (Earth-TRN757); 1st Appearance of the High Council (Earth-TRN757) |
| 5 | Marvel Comics Presents (3rd Series) | 1st Appearance of Doctor Strange (Earth-TRN758); 1st Appearance of Shadowcat (Earth-TRN758); 1st Appearance of Wong (Earth-TRN758); 1st Appearance of X-Men (Earth-TRN758); 1st Appearance of Nightcrawler (Earth-TRN758); 1st Appearance of Professor X (Earth-TRN758); 1st Appearance of Storm (Earth-TRN758); 1st Appearance of Yukio (Earth-TRN758) |
| 2/A | Marvel Masterworks: Atlas Era Tales to Astonish | 1st appearance of Gorgilla; 1st appearance of Groot; 1st appearance of Krang; 1st appearance of The Blip; 1st appearance of Vandoom; 1st appearance of Rommbu; 1st appearance of X the Thing That Lived; 2nd appearance of Gorgilla; Collects Tales of Suspense (Vol. 1) #11-20; Introduction by Mike Allred; ca. 2008 |
| 2/HC | Marvel Masterworks: Atlas Era Tales to Astonish | 1st appearance of Gorgilla; 1st appearance of Groot; 1st appearance of Krang; 1st appearance of The Blip; 1st appearance of Vandoom; 1st appearance of Rommbu; 1st appearance of X the Thing That Lived; 2nd appearance of Gorgilla; Collects Tales of Suspense (Vol. 1) #11-20; Introduction by Mike Allred; ca. 2008 |
| 8 | Military Comics | 1st appearance of X of the Underground; Blackhawk |
| 2 | Millennium | 1st appearance of Salima Baranizar; 1st appearance of Betty Clawman; 1st appearance of Gregorio de la Vega; 1st appearance of Janwillem Kroef; 1st appearance of Nikolai Latikov; 1st appearance of Xiang Po; 1st appearance of Celia Windward; 1st appearance of Takeo Yakata |
| 2/NS | Millennium | 1st appearance of Betty Clawman; 1st appearance of Celia Windward; 1st appearance of Gregorio de la Vega; 1st appearance of Janwillem Kroef; 1st appearance of Nikolai Latikov; 1st appearance of Salima Baranizar; 1st appearance of Takeo Yakata; 1st appearance of Xiang Po |
| 2 | Millennium (Canadian Edition) | 1st appearance of Betty Clawman; 1st appearance of Takeo Yakata; 1st appearance of Xiang Po; 1st appearance of Nikolai Latikov; 1st appearance of Celia Windward; 1st appearance of Salima Baranizar; 1st appearance of Janwillem Kroef; 1st appearance of Gregorio De La Vega |
| 2 | Mr. and Mrs. X | 1st appearance of Xandra |
| 2/A | Mr. and Mrs. X | 1st appearance of Xandra |
| 10 | Mutant Misadventures of Cloak & Dagger, The | 1st appearance of X-Force (villains) |
| 10/NS | Mutant Misadventures of Cloak & Dagger, The | 1st appearance of X-Force (villains) |
| 42 | New Adventures of Superboy, The | 1st appearance of Fire Devil; 1st appearance of X-Rayder; 1st appearance of Lavender Skywriter; Dial “H’” for Hero; Superboy |
| 42/NS | New Adventures of Superboy, The | 1st appearance of Fire Devil; 1st appearance of Lavender Skywriter; 1st appearance of X-Rayder; Dial “H’” for Hero; Superboy |
| 100 | New Mutants, The | 1st appearance of X-Force; Death of Brute; Origin of Shatterstar (Benjamin Russell) |
| 100/NS | New Mutants, The | 1st appearance of X-Force; Death of Brute; Origin of Shatterstar (Benjamin Russell) |
| 24 | New Teen Titans, The (1st Series) | 1st appearance of X’Hal; 1st appearance of Blackfire (named as such) |
| 24/NS | New Teen Titans, The (1st Series) | 1st appearance of Blackfire (named as such); 1st appearance of X’Hal |
| 24 | New Teen Titans, The (1st Series, Canadian Edition) | 1st appearance of X’Hal |
| 3 | Nyx | 1st Appearance of X-23 |
| 3/NS | Nyx | 1st Appearance of X-23 |
| 2 | Peter Porker, the Spectacular Spider-Ham | 1st appearance of X-Bugs |
| 2/NS | Peter Porker, the Spectacular Spider-Ham | 1st appearance of X-Bugs |
| 2 | Peter Porker, the Spectacular Spider-Ham (Canadian Edition) | 1st appearance of X-Bugs |
| 1 | Point One | 1st Appearance of X-Termintaed; 1st Appearance of Coldmoon; 1st Appearance of Dragonfire; Death of Terrax |
| 1/A | Point One | Death of Terrax; 1st Appearance of Coldmoon; 1st Appearance of Dragonfire; 1st Appearance of X-Termintaed |
| 1/B | Point One | Death of Terrax; 1st Appearance of Coldmoon; 1st Appearance of Dragonfire; 1st Appearance of X-Termintaed |
| 27 | Power Man & Iron Fist | 1st appearance of X the Marvel |
| 1 | Powers of X | 1st Appearance of the Man-Machine Ascendancy (Earth-TRN753); 1st Appearance of Librarian (Earth-TRN753); 1st Appearance of Nimrod the Greater (Earth-TRN753); 1st Appearance of the Man-Machine Supremacy (Earth-TRN756); 1st Appearance of Nimrod the Lesser (Earth-TRN756); 1st Appearance of Omega Sentinel (Earth-TRN756); 1st Appearance of Theta Sentinel (Earth-TRN756); 1st Appearance of Post-Humans (race) (Earth-TRN753); 1st Appearance of Wolverine (Earth-TRN753); 1st Appearance of X-Men (Earth-TRN753); 1st Appearance of Cardinal (X-Men) (Earth-TRN753); 1st Appearance of Cylobel (Earth-TRN753); 1st Appearance of Rasputin IV (Earth-TRN753); 1st Appearance of X-Men (Earth-TRN756); 1st Appearance of Cardinal (X-Men) (Earth-TRN756); 1st Appearance of Cylobel (Earth-TRN756); 1st Appearance of Last Horsemen of Apocalypse (Earth-TRN756); 1st Appearance of Death (Xorn) (Earth-TRN756); 1st Appearance of Famine (Cypher) (Earth-TRN756); 1st Appearance of Pestilence (North) (Earth-TRN756); 1st Appearance of War (Wolverine) (Earth-TRN756); 1st Appearance of Percival (Earth-TRN756); 1st Appearance of Rasputin IV (Earth-TRN756); Includes packet of Krakoa Seeds; Crossover Miniseries with House of X; Part 2 of 12; Story continued from House of X #1; Story continues in House of X #2 |
| 7 | Runaways (2nd Series) | 1st appearance of Xavin |
| 7/NS | Runaways (2nd Series) | 1st appearance of Xavin |
| 9 | Savage Hawkman, The | 1st appearance of Xerxes |
| 9/NS | Savage Hawkman, The | 1st appearance of Xerxes |
| 1 | Silver Surfer: The Best Defense | 1st Appearance of The Conductor; 1st Appearance of Goldie (Centaurion); 1st Appearance of Scab Tongue; 1st Appearance of X’anth; Story continued from Doctor Strange: The Best Defense Vol 1 #1; Story continues in Defenders: The Best Defense Vol 1 #1 |
| 23 | Superman (5th Series) | 1st appearance of Xanadoth; 1st appearance of Veronica Bissette |
| 215 | Thor | 1st Appearance of Xorr |
| 215 | Thor (UK Edition) | 1st Appearance of Xorr |
| 1 | True Believers: Hulk—The Other Hulks | Reprints 1st appearance of Xemnu the Living Titan; Reprinting material from Journey Into Mystery (1950) #62, Strange Tales (1951) #75 |