most of his knowledge is in the vampire slaying category, I think he might have trouble making the transition into zombie slaying.
anyone saying batman is a moron, hes just a rich pretty boy. he would have a mental breakdown if there was a zombie apocalypse. (no offense bruce - your my boy.)
Aqua man would have it too easy - so I have to say its a 3 way tie between superman, ironman, and the hulk. my bets are going on iron man though. tony could handle a zombie apocalypse like it was his job.