The Logitech mx518 Jack Flak suggested is pretty solid. I got it because of the dpi-on-the-fly without the need for drivers (sweet!).The G5 & G7 are also good choices, if your willing to spend the extra cash. I've heard that Razor has some good mice as well, but I've never personally handled one myself.
I may be bested in battle, but I shall never be defeated.
I've been using the Razer for about two years now and I love it. You can get the Copperhead for about $49 at Amazon. It has the four side buttons which can be bound to whatever, plus it slides on their eXactMat like an air hockey puck. The DPI adjustment is on the fly, but I am pretty sure it requires the drivers (been a while since I installed it).
I like heavy mice and the G5 is heavier than any other I've tried. It scrolls smooth, the dpi adjustment is intuitive and easy to use, the fire buttons don't wear out and the pads are nice and slippy without making it feel unstable.
Oh and all this is without installing some useless app for key management.
Yeah, that was the only downside to my Razer; the weight. It was a little to light. I opened it up and threw some lead weights in it, and it's perfect. At the time I couldn't find a left handed gaming mouse since that's how I play, they were all molded for righty's. This was ambidextrous, which was a plus.