I could never understand why the "Hitler didn't really commit suicide, he was killed" trope is so popular.
Personally, I think that committing suicide is a perfect ending for such an evil bastard, because it shows that he realized he had lost and was fucked. Somebody killing him grants him a "he fought on until the very end!" honor he really didn't deserve.
I really liked that issue of the Midnighter where Midny goes back in time to kill Hitler, but relents when he sees how utterly pathetic the defeated Hitler is.