I'm very wary about buying brand-name computers now b/c the things are built as cheaply as possible, and the parts used are generic and often sub-par. (I bought one compaq that was D.O.A. the first time I used it, and i had to drive all the way back to return it. ) If one thing breaks, there is often no warranty for it.
If you buy a computer for games, be sure that it has a real video CARD and not just a video chipset on the motherboard--- chipsets suck b/c they don't have their own dedicated memory like cards do, and this means that chipsets always use up some of your system RAM.
Also, the software on compaq/emachines/etc. totally blows... you get a "restore disc" but it's not a real copy of windows, it is a HD image that reloads a sh!tload of useless memory-wasting proprietary software along with windows, so you never get a clean instalation.
the absolute best way to get a computer is to buy good quality brand-name parts and assemble it yourself. That way, you get exactly what you want and each part has its own warranty.