It depends upon the level at which you play games.
If your an avid gamer, there is not much question that a CRT will be better for you than a TFT, but I'm talking about serious gaming. If it's occasional use, the TFT is more than adequate, and the speed of response and so on will have improved in the last five years.
I use a TFT, although I confess to not being an avid gamer and find it perfectly satisfactory. Oh, and I can run Flight Sim on a 17 inch with no problems.