The Dark Knight
Adam West
Batman (TV series), Batman: The Movie

Michael Keaton
Batman, Batman Returns

Val Kilmer
Batman Forever

George Clooney (seriously, what genius thought this was a good idea?)
Batman and Robin

Kevin Conroy (voice)
Batman: The Animated Series (TV series), The Adventures of Batman & Robin (TV series), The New Batman Adventures (TV series), Batman: Mask of the Phantasm, Batman: Sub-Zero, Justice League (TV series), Batman: Mystery of the Batwoman

Christian Bale
"Batman 5" presently pre-production; great Caesar's ghost, this is going to be fantastic!