Samsung, Hannspree, and Dell make good monitors at different price ranges.
I can't speak too well on monitors as, though I have a rig that plays this game at relatively high settings, budget cuts force me into an old 15" CRT monitor with 'wrapping' lines up top.
For a monitor, you want it to be 1920x1200 capable (That would be 1080p equivalent), have a 5mhz response time or less, and have connections that match your video card. Most newer Nvidia cards have DVI and HDMI out, so I assume your ATI is the same (DVI is around an inch and a half long, rectangle slots, and white. HDMI looks like a hat. VGA is usually blue, sometimes pink, with a trapezoidal shape and round slots).
Glossy or flat is preference. I prefer the sharp image of glosssy, but it does best in low-light, whereas flat is still good, but slightly better in light, slightly (very) worse in the dark.
Other than that, stick to a decent budget. Shop online instead of in stores (newegg.com is the site I use)
Edited, Nov 20th 2010 12:54am by jaysgsl