The Firefighter Axe.
Using it to kill zombies is a secondary option, the axe is great for busting down doors (especially since it's in a Zombie Apocalypse, almost every door to useful supplies are locked, so how are you going to barge in?).
Also, if we had an option for a Laser Cannon, why not have a Steel Knight armor? That's the best way to survive, since zombies can't bite through steel. :D