BenQ monitors seem to be liked on some gaming sites because of their fast response time but I have never owned one. IMO I would just browse around a few review sites and gaming forums since there so many to choose from.
If you are using the monitor for just games, could you just get a TV?
I use a HP2475w for gaming, computing and movies (Bluray and upscaled DVD) and looks great. After I fiddled around with the contrast/brightness and colours I noticed details in textures that I never realised were there.