Days of Future Piff
All Star
30. Casper the Friendly Ghost by Seymour Reit and Joe Oriolo
29. Astro Boy by Osamu Tezuka
28. Amar Chitra Katha by Amar Chitra Katha Pvt. Ltd.
27. Slam Dunk by Takehiko Inoue
26. Bleach by Tite Kubo
25. Avengers by Marvel
24. Oishinbo by Tetsu Kariya and Akria Hanasaki
23. Garfield by Jim Davis
22. The Phantom by Lee Falk
21. Spawn by Todd McFarlane
20. Diabolik by Angela and Luciana Giussani
19. KochiKame by Osamu Akimoto
18. Case Closed by Gosho Aoyama
17. Spike and Suzy by Willy Vandersteen
16. The Adventures of Tintin by Herge
15. Golgo 13 by Takao Saito
14. Captain America by Marvel
13. Naruto by Masashi Kishimoto
12. Dragon Ball by Akira Toriyama
11. X-men by Marvel
10. Lucky Luke by Morris, Rene Goscinny
09. Peanuts by Charles M. Schulz
08. Asterix by Rene Goscinny, Albert Uderzo, and Jean-Yves Ferri
07. Spider-man by Marvel
06. One Piece by Eiichiro GOATda
05. Batman by Bob Kane and Bill Finger
04. Superman by Jerry Siegel and Joe Shuster
03. Classics Illustrated by Elliot Publishing Co., Gilberton Company, and Frawley Corporation
02. The Beano by DC Thomson
01. Micky Maus (Mickey Mouse) by Egmont Ehapa
Note: X-men vol. 2 #1 (by Chris Claremont and Jim Lee) is the best selling single-issue of any comic, having sold over 8 million copies.
29. Astro Boy by Osamu Tezuka
28. Amar Chitra Katha by Amar Chitra Katha Pvt. Ltd.
27. Slam Dunk by Takehiko Inoue
26. Bleach by Tite Kubo
25. Avengers by Marvel
24. Oishinbo by Tetsu Kariya and Akria Hanasaki
23. Garfield by Jim Davis
22. The Phantom by Lee Falk
21. Spawn by Todd McFarlane
20. Diabolik by Angela and Luciana Giussani
19. KochiKame by Osamu Akimoto
18. Case Closed by Gosho Aoyama
17. Spike and Suzy by Willy Vandersteen
16. The Adventures of Tintin by Herge
15. Golgo 13 by Takao Saito
14. Captain America by Marvel
13. Naruto by Masashi Kishimoto
12. Dragon Ball by Akira Toriyama
11. X-men by Marvel
10. Lucky Luke by Morris, Rene Goscinny
09. Peanuts by Charles M. Schulz
08. Asterix by Rene Goscinny, Albert Uderzo, and Jean-Yves Ferri
07. Spider-man by Marvel
06. One Piece by Eiichiro GOATda
05. Batman by Bob Kane and Bill Finger
04. Superman by Jerry Siegel and Joe Shuster
03. Classics Illustrated by Elliot Publishing Co., Gilberton Company, and Frawley Corporation
02. The Beano by DC Thomson
01. Micky Maus (Mickey Mouse) by Egmont Ehapa
Source: The 30 Best-Selling Comic Book Series of All Time | Best Life
This list was made in 2018, idk if anything has significantly changed since then.
Note: X-men vol. 2 #1 (by Chris Claremont and Jim Lee) is the best selling single-issue of any comic, having sold over 8 million copies.