Look at the Viewsonic VA720 for an affordable 17" model. I have used one for a few things and Quake3, Foresaken, and Half-Life run fine on it. I can get noticable ghosting during Motocross Madness2 though. Not bad enough to bother you though...
Other models I would go for is the Viewsonic VG700 and the Samsung 172n with the Samsung being the best of the 17" available IMHO.
For just a few bucks more, you can go for the 18" Viewsonic VG800b which is a very good LCD.
I have a 172T Samsung 17" monitor.
To be honest I think I'll use it for everything but gaming and keep my 19" Samsung 957DF CRT for gaming.
With a response time of <24ms it still suffers quite noticeable ghosting. I'd look at AOC monitors. Their colour reproduction might not be as sweet as the Samsungs but they have ~14ms response times which will result in little or no ghosting. The other limiting factor to consider with LCDs is the fact that they work best when running in their native resolutions (1240x1024 for a 17"). Also I recommend using DVI connection if your graphics card supports this, as this will give you the clearest, best image on screen.