If you're looking for a good multi-effect pedal that's reasonably priced, you might want to check out the Digitech RP series. I've had an RP150 (about $150) for about a year now, and I love it. Got some really good sounds out of an OLP Axis knockoff that didn't have much bite to it and my Crate GT-80. With the real Axis it sounds phenomenal.

Plus, it's just really fun to play around with and see what kind of sounds you can create.

I don't know how well it would work in a live setting or with a bigger amp setup, but it rocks the heck out of my living room. :D