Logitech MX Revolution. Great mouse, had it for over 3 years now. Great for games 'cos you can map all the keys to keypresses on an application specific basis with the Setpoint software. Battery is starting to lose it's ability to hold charge so I have to put it in it's cradle everyday if I'm playing a lot of games. Sadly it's been discontinued so when it dies I'll have to get the updated model which to mine eyes doesn't seem as good. Hoping Logitech release a new flagship mouse before then.