My friend bought me a microsoft Intellimouse 3 or 4 years ago. I love it! its worked beautifully for me all these years and I have had no complaints or skipping of any kind. I play intense FPS's all the time
I was looking to get another at frys but they still cost 25$! I was surprised that after all these years, you'd think that the basic intellimouse would drop price. Maybe they use the newer technology, but I didn't see that mentioned on the box.
Anyways, I saw Office Depot has something like "microsoft basic optical mice" for sale for 10 bucks
I may go check it out.
Oh, btw I saw the MX510 in stores the other day. Its very cool IMO! I would get it in a heartbeat IF it wasn't so expensive. But for now, the basic microsoft mouse is my choice