a knife. because you have to get way too close
OK first off. Knives outside of being weapons are extremely important and versatile. Not just for cutting but as a tool in general.
When I think of bad weapons I think of shit that I could grab at any given moment. Like I would prefer not to use this keyboard but I would if I couldn't come up with a better idea at that time. (maybe this printer...or this never mind...)
I wouldn't use a box cutter, a coat hanger (unless I was able to straighten it and had a clear shot for an eye socket), a rolled up newspaper, a CD, I could go on...
I mean hell I would swing around an ironing board if I had too
As far as actual weapons I don't think I would want to be they guy that has an axe (logging, pick, or battle). I am no expert but even if was fluent in the ways of axe wielding I know that it generally takes a lot of energy to swing one not to mention if you do land a solid blow to the skull, then what... you gotta get it out. By that time your swarmed anyway. Good thing you got that "one".
A shovel on the other hand gives you stand off. Its narrow and has a grove to reduce suction within the cavity so slightly easier "pull out" if you will. Down side. If you have one you pretty much have to carry it by hand since its going to run the length of your body and having it tied to your back, however you may do that, its going to be cumbersome. Still, bash 'em, knock 'em down, then... you get the idea.
The worst, in my opinion, overall; the chainsaw. It works great to kill a zed in the movies, but in real life it is useless. the fuel is finite, it is loud and noisy, and can easily snag on bone of a zombie and send it flying out of your hands, or snap the chain and injure you. Unless you hace a specially modified (maybe make it silent, on a pole?) one, avoid this. One slip can send this flesh-ripping machine into your head as easily as the zombei you are fighting.
Oh yeah, Dead Rising!
and already made