A comic book miniseries published by Marvel and DC Comics in late 2003. The series was written by Kurt Busiek, with art by George Perez. Each of the four issues of the series was 48 pages long and sold for a whopping six bucks!
Obviously, the series covers a team-up of DC's JLA and Marvel's Avengers, the two comics companies' premier superteams. Busiek and Perez have both worked on "The Avengers" together and have said that they intend to include every character who has ever been a member of either team, which, luckily, plays right into Perez's ability to draw absolutely huge numbers of characters and detail on every page.
Perez, in fact, has been lobbying to make this comic for the last couple of decades and has released sketches and finished artwork he did in the 1980s of his vision for the book. In the past, Perez's efforts were hampered by both low sales numbers for previous incarnations of the Avengers and the Justice League and by the inability of Marvel and DC to cooperate on bringing the project to completion. Luckily for comic book fanboys, the two companies finally decided to put their differences aside and try to rake in metric buttloads of cash.
What can we expect from the plot? Bet on cosmic supervillains and evil schemes that threaten the existence of both the Marvel and DC universes. Plan on watching two teams supposedly dedicated to ensuring peace on earth mistake each other for supervillains on their first meeting, then start beating each other up for an issue or two (though don't expect to see one team defeat the other, 'cause you can't go hurting the towering egos of these comic book companies, oh no. Just think how DC's stock would plummet if Gilgamesh the Forgotten One managed to beat up Vibe), but they'll realize that they're on the same side in time to join forces and pull off a last-second win against the forces of darkness. But after that, no one on either team will ever mention their dimension-hopping adventures again.
So what happens? Check the links below...
JLA/Avengers #1
JLA/Avengers #2
JLA/Avengers #3
JLA/Avengers #4