Sure LCDs can't match CRTs in terms of picture quality...
But CRTs have the low refresh rates which leads to strain on your eyes.
And CRTs are HUGE compared to LCDs, which means more weight and more space taken up on your desk.
For a new gaming monitor, I would highly recommend a 20" LCD...try looking at the Samsung or the Viewsonic VX series of widescreen monitors. Very high quality.
As towely said, any game can be tweaked to run in widescreen...although more and more games are coming up with that option built-in.