AHHH, finally a mouse poll!!
here's my 2 cents: personally, i use a logitech first mouse with scroll (this is a ball mouse). from experience, playing quake, i think it's safe to say that OPTICAL MICE aren't as good as BALL MICE for gaming. the reason being, when you're racking up the frags, your mouse frequently goes off the pad. With a ball mouse, the ball will still have momentum, thus you keep moving. however, with an optical mouse, you stop completely. In quake this could mean the difference between killing or being killed.
The best ball mouse i have EVER seen for gaming would have to be the logitech mouseman with scroll. they stopped making it, but it conforms to your hand, and has a thumb button.
quad