I support the statement that we cannot exactly decide it for you. Something I like won't necessarily fancy your taste. Furthermore, it depends on the type of games as well. Some mouse is better suited for fps games while some suits mmo/rpg. The build quality is a key factor and Logitech units excel in it (IMO of course). My personal all time favorite is the MX 518.
I've used the mx518 for 5 years now and it still is one of the best mice I ever owned. Essentially you have to ask yourself:
Do I want wireless or wired (i prefer wired)?
What DPI do I want?
Do I need extra buttons i.e. mmo type of mouse with keypad?
The top mice makers (i.e. microsoft, logitech, and others) have excellent gaming mice. You can look at the reviews.. Then go to computer shops like Best Buy, Fry's etc that will enable you to try it. Get the feel of the mice w/ your hands.
Wired mice always perform better than wireless although there are great wireless gaming mice that came out.
Specially on on-line first person shooting game... Can't afford the lag time of wireless mice.
Read the specs/review... then try it on the stores find out what it comfortable in your hands.
The mx518 is my favorite mouse. It has a great feel to it when you have it your hands. Movement is very fluid when moving. The card is also durable as it is very reliable. There is also the second coming of the mouse g400 ,which has many improvements to the single best selling gaming mouse of all time
I own a MX518 and a Razer Goliathus medium sized mouse pad. The mouse pretty much fits to your hand . Its slightly heavier than the normal mice but with a smooth mouse pad (buy the razer ones, they are good) you can enjoy very comfortable FPS gaming. i would give it 9 on 10. Ive used the deathadder too. That is a v comfortable mouse too. It has a higher DPI rating.. But i prefer the MX518 since i like the grip better. Once you buy a good gaming mouse pad , your crosshair or the mouse pointer will move fluently without any effort..