I haven't spent much time looking at the iMac flat panel display, but I have the 17" Apple Studio Display flat panel. I'm very happy with it, although it tops out at 1280x1024 resolution. Many 3rd party 17" flat panels are capable of higher resolutions, but for me 1280x1024 is perfect, and I doubt I'd use anything higher on a 17" display.
It's great for gaming, and the extra USB ports on the back are a nice touch. It's a great display for any use short of professional graphics. A good CRT is probably still best for that kind of work.
the picture quality's probably similar, but might be better on the imac as it's a newer design. for video i'd go wwith the imac (it's widescreen) but for games (some dont like widescreen resolutions and you might be required to play with parts of the screen black) go for the studio display
You have to be careful when playing games on an LCD display. LCD's only work best at their native resolution, which is 1280x1024 for a 17" Apple LCD Display; the image and quality actually drops when the native resolution is not set. Therefore, if you played a game at 640x480 resolution on a 17" LCD with a native resolution of 1024x758, the overall quality of video would actually drop (the drop in quality really does vary; blurryness can occur; "your meliage may vary.") as the LCD is no longer at its preferred native resolution. When being a hardcore gamer, and you play different games at different resolutions, CRT monitors are indeed better.
Also, if you're intending on getting an LCD display, unless looks really matter to you, get an LCD that isn't from Apple - ViewSonic sells LCD displays for less than what Apple wants for theirs for the same size (exlcuding the 23" model) with a higher contrast ratio and better quality (Apple LCD's are a 350:1 ratio, while View Sonic LCD's are up to 800:1 from 500:1 contrast ratio and cost less). They also don't require a ADC (Apple Display Connector) connector.
[ November 12, 2003, 10:00 AM: Message edited by: Lars ]
Sounds to me like you may be looking at upgrading or buying a new computer. If that's the case, a G4 1.25 with a Viewsonic 17" (or 18" from Costco) is cheaper than or near the same price as the 17" iMac. The tower is, IMHO, a much better option.