The explosion in comic book-related films in the last few years isn't confined to the big screen, or to live action. Both of the "big two" comic book publishers, DC Comics and Marvel Comics, have released a number of high-quality direct-to-DVD animated features based upon their characters.
According to Wizard magazine and The-Numbers.com:
Superman: Doomsday - 9.4 million
Batman: Gotham Knight - 8.0 million
Ultimate Avengers 2 - 7.8 million
Ultimate Avengers - 6.7 million
Hulk Vs. - 5.4 million
Invincible Iron Man - 5.2 million
Justice League: The New Frontier - 5.2 million
Dr. Strange - 3.9 million
Wonder Woman - 3.4 million
Next Avengers - 2.9 million
Marvel's next animated release is Thor, designed to raise interest in the character slated for a live-action feature film in 2010. DC is releasing the animated origin story Green Lantern: First Flight in July.
Green Lantern: First Flight debuts July 28th!