I'm using the Cyborg R.A.T 9 and its awesome, I definitely recommend it, it has great wireless and you can customize a lot of its shape to suit the way you want to hold the mouse. Its quite expensive, but the next model down, the R.A.T 7 is the same mouse but wired instead of wireless, which you can get cheaper. Buttons on the mouse allow you to change the DPI ingame and there is a button where your thumb rests which slows down your DPI when you hold it down, which is pretty useful particularly in FPS games. It also even has weights you can add or remove to make your mouse even more suited to you. If you've got the money, this mouse is awesome.