anything under 4ms = excellent
anything under 8ms = not to shabby
anything under 12ms = passable, unless you're a super twitchy gamer, or playing something really flashy like quake
anything over 12ms = don't. just don't.
As for brands, I've always had LG monitors, never had any complaints, but alot of people make quality LCD screens, so I wouldn't really limit yourself to a small number of brands

Try finding a review of monitors on PCgamers magazine, or any of the other mags. I'd find links for you but I'm dead tiread and need to be in bed