Actually, the 27" iMac has a beautiful screen. I find it's kind of too large, though. I mean, honestly, 27" is a TON of real estate. And some games don't scale. StarCraft 2, for instance, shows you exactly as much on a 27" iMac as it would on a 13" laptop. WoW is OK on it, but again, there's actually too much area for your eyes to cover quickly. Sitting too far back from the screen kind of renders having a large display pointless, too. That's why people get various sized TVs: You get a larger TV if your couch is further back, and a smaller one if your couch is closer.
Some of the best deals on computers occur at refurbished laptop/computer sites (eg, http://www.cheetahdeals.com/Refurbished_Laptops_s/... I know they're not as "sexy" as buying a new iMac, say. But there's nothing sexy about being broke, either!