17" monitors look better at 1024x768, which is the standard resolution for gaming. If you want to play higher than 1024x768, it will require much more frequent video card upgrading. 19" monitors, because of their larger pixel size, give you a washed out image at 1024x768, which makes the games look plain ugly. Go for a 17" if you want a good life out of your graphics card.
Other than that, I have no complaints about my LCD, and really would not use a CRT again except for the reason I stated above.
