Depends on the gaming mouse you want.
Do you want wireless, or wired?
I have the RAT 9 - wireless mouse. It's really great, and I find it comfortable. I don't use the weights that come with it because it makes the mouse too heavy though. It's adjustable to boot. A single charge usually lasts me a good 7-8 hours (it comes with 2 rechargeable batteries, one to use for the mouse, while the other charges). It's kind of expensive though.
The RAT 7 is a wired mouse. Same as the RAT 9 except for the wired part.
I've heard other people liking the razor naga. But I guess it really depends on preferences.