Well to be honest I play mainly FPS games and since switching weapons and using equipment is usually the number keys if it isn't then you can change it. I would suggest the razer naga. I am not a fan of their keyboards but they make a damn fine mouse, The razer naga feels nice as well as being responsive. The number keys and other keys on the mouse make it easy for you to change weapons without using the scroll wheel and stop you from taking your fingers off wasd to click a button like e or g. This is good for games like Call of duty, counter strike and battlefield. If you don't want the buttons and just want a normal mouse then I would go for the razer deathadder that is a great mouse too with some buttons that you can key bind. Both of the are a great choice and it is up to preference to choose which one you want.
Razer naga: http://www.amazon.com/Razer-Naga-MMO-Gaming-Mouse/dp/B00E8CF268/ref=sr_1_1/175-8153509-4421765?ie=UTF8&qid=1432594333&sr=8-1&keywords=razer+naga
Razer Deathadder: http://www.amazon.com/Razer-DeathAdder-Chroma-Multi-Color-Ergonomic/dp/B00MYTSDU4/ref=sr_1_1?ie=UTF8&qid=1432594757&sr=8-1&keywords=razer+deathadder