I have a logitech LX5, absolutely best mouse I've ever owned.
I like to keep it simple, it fits in my hand good, the invisible optic gets mad amounts of battery life (the wireless mice I had before it would undergo battery changes once per month or more) this one goes for 4 months and then the low battery light goes on and it goes for another 2 months.
I'd rank it as perfectly ideal, it has 5 buttons (3 in the scroll wheel: down, left, right) It's simple, comfortable, precise, and I only have to fumble for batteries a couple times per year.
I'm also fond of the thinkpad track point as far as notebook pointers (although it's not as easy to master as a mouse, it's the only alternative built on to notebooks to the touch pad
) - touchpad is good too, but sometimes I like the track point instead.