Even for the same price I would go for a CRT monitor. Why? Although TFT displays are nice and thin and irradiate you less, they only have one 'native' resolution. For a typical 15" TFT screen, this is 1024x768. If you game a lot you will want to go higher than this. This is simply impossible on such a TFT - it only has 1024x768 physical pixels and no amount of software control can make it go higher.

The same applies for lowering resolution. Say you have a mediocre graphics card but want to run Quake III Arena with full detail. You will need to lower the resolution to, say, 800x600. Although this is possible with a TFT screen, because 1024/800 and 768/600 do not divide exactly, the screen must interpolate to get this lower resolution using the 1024 and 768 pixels it actually has in hardware. When is interpolates the picture quality is poor. So unless you just use your PC for fixed-res Windows use, dont do it! - don't buy a TFT screen.

Added bit for The Custodian: Some of us power hungry gamer geeks most certainly do want higher than 1024x768. I agree that for RTSs this just hurts. However most FPSs look nicer the higher the resolution you put them in. Games like Homeworld look plain blocky to me in 1024x768. Bear in mind too that a 15" TFT's viewable area isn't that much different from a 17" CRT. As you say - if you use your PC all day for work - TFTs are cool. For the power gamer I'd say CRT all the way.