For better precision on gaming you want optical and my top 3 are, Mionix Naos 7000, Steel Series Rival and Zowie.
Not interested in laser at all, I already got a couple.
The G100s is where it's at! Flawless optical tracking and incredibly lightweight (I modded mine to bring it down even further to about 65 grams). Plus it's only $35 to start with. If you need an entry-level gaming mouse that outperforms a lot of more expensive mice, get one of these.
In FPS gaming you almost always want to have an optical mouse to reduce interpolation and mouse acccel. The Zowie FK, SteelSeries Rival and Razer Deathadder are all optical mouses so if you're looking for a mouse for shooters that's gonna be what you want.