i use the good ol' Genius Netscroll that came with my computer and a dodgy mousepad with the shops logo on it
i'll probably get slammed for saying this but, as long as your mouse is comfortable to use (which most are these days) i think questions like this: Does anyone know which is better for gaming? is stupid. i have friends that i LAN with that have logitech gaming mouses and everglide gaming pads and stuff like that, but i am still way better at using the rail gun in q2/q3a than any of them. i can get better accuracy than them when i use an old serial mouse and they use a usb/ps2 mouse. for gaming, skill is more important than the price you pay for your mouse/pad.
im not trying to say im unbeatable with the rail or anything . im just saying that alot of people expect a mouse to increase their skill. like most things, it all comes down to practice.
ok, im done now