Just replaced my trusty Microsoft IntelliMouse (ball) with the IntelliMouse Explorer (optical). No more cleaning the ball, no more skipping on dirty surfaces, and the tracking is noticeably smoother.

If you're still using a ball mouse, upgrade immediately. Optical mice are like $25 now and the difference is night and day.

Made the switch 6 months ago and I will never go back. The ball mouse cleaning ritual (pop the ring, clean the rollers, blow out the dust) was my least favorite computer maintenance task.

The Logitech MX300 is an excellent budget optical mouse. $20 and it tracks perfectly on any surface. No more mouse pads!

For gaming specifically, the Microsoft IntelliMouse Explorer 3.0 is the gold standard. Perfect shape, perfect sensor. Every serious gamer I know uses one.