The only death battle fight I really enjoyed was the Spider-Man vs Batman. Terrible mismatch, but a good fight.
I loved the Dr. Willy vs Dr. Eggman..
and the Zelda vs Peach was fun! tho Zelda should had won.
@Destinyheroknight: That doesn't mean anything anymore especially since they specifically said they won't use anything about the retconned Superman =P
@ReiKai: He still loves Lois. He revealed that it's just that she moved on so he had to too. I don't think he had sex with her though. That's not Superman's style.