#1 Superman ( 600 million-plus )
The character Superman began as one of several anthology features in the National Periodical Publications comic book Action Comics #1 in June 1938. The strip proved so popular that National launched Superman into his own self-titled comic book, the first for any superhero, premiering with cover date June 1939.
#2 Batman ( 460 million-plus )
The character first appeared in Detective Comics #27, published in May 1939. Batman proved to be so popular that a self-titled ongoing comic book series began publication in the spring of 1940. It was first advertised in early April 1940, one month after the first appearance of his new sidekick, Robin, the Boy Wonder.
#3 Spider-Man ( 360 million-plus )
The bite of an irradiated spider granted high-school student Peter Parker incredible powers. When a burglar killed his Uncle Ben, Peter vowed to use those abilities to protect his fellow man, driven by his uncle's words: With great power comes great responsibility!
#4 One Piece ( 345 million-plus )
One Piece is a Japanese manga series written and illustrated by Eiichiro Oda. It has been serialized in Weekly Shonen Jump since August 4, 1997; the individual chapters are being published in tankobon volumes by Shueisha, with the first released on December 24, 1997, and the 73rd volume released as of March 2014.
#5 X-Men ( 270 million-plus )
X-Men is a comic book ongoing series published by Marvel Comics featuring its namesake superhero team.The 2010 X-Men series was the third ongoing series to launch with the title following the first series in 1963 and the second series in 1991.
#6 Captain America ( 210 million-plus )
Captain America is an American fictional character, a superhero who appears in comic books published by Marvel Comics. The character first appeared in Captain America Comics #1 (cover-dated March 1941), from Marvel Comics 1940s predecessor, Timely Comics, and was created by Joe Simon and Jack Kirby.
#7 The Adventures of Tintin ( 200 million-plus )
The Adventures of Tintin (French: Les Aventures de Tintin) is a series of comic albums created by Belgian cartoonist Georges Remi (1907–1983), who wrote under the pen name Herge. The series was one of the most popular European comics of the 20th century, and it remains popular today.
Updated List, added one more to it
#8 The Phantom ( 150 million-plus )
The Phantom is an American adventure comic strip created by Lee Falk, also creator of Mandrake the Magician. A popular feature adapted into many media, including television, film and video games, it stars a costumed crime-fighter operating from the fictional African country Bangalla.