Sledge Hammer

It could do a high amount of pummeling damage but take a while to recover from its swing. You can find these at a lot of houses in a shed of back by a wood pile. Another location could be along a railroad where the sledge could of once been used as a rail nail driver. Think about it...
EDIT: Here's another one. Cleaver!

It is found in most kitchen and who wouldn't want to hack through a few zombies with an ordinary kitchen cleaver.
More edits: Garage tools...

A screw driver could add to the fun of stabbing a few zombies with your everyday screwdriver.
Even More edits: A lead pipe!

Bash a few zombies over the head with this feller and you will surely cause some trauma. This can be found in worn down houses or industrial areas.