Definitely the Razer Viper ultimate wireless, it's light, fits very well in the hand and has good glides, perfect for fpp and rts games, the best mouse I've had so far, I've had a lot of mice. Of course, for mmo games I recommend the Corsair Scimitar in which you can set many additional buttons as a macro, unfortunately it is not good for fpp games, its large size and additional buttons make it difficult and slow to precisely aim.