look at the Harmonic Quad Zapper too.

I bought the ultimate zapper recently & started to use it two weeks ago. It surely works well. My decision was based on the fact that it has a power adapter. It doesnt look pretty like some other zappers out there...but its surely cost effective in the long run, in my opinion.

Heard that the termiator II is good too, although a very different kind of zapper.

Good luck!