Build-To-Order PCs?

Anyone got a good, trusted site where I can configure a good (hopefully under $500) machine. I’m looking for a computer that can run good games, but not necesarily a “Gaming Machine” per say. I need a good graphics card (Nvidia or ATI), at least 1024 mb ram and preferably an Intel Core 2 Duo CPU.
Also, bundled OSes are bad…I like LINUX! Bundled harddrives = :frowning: I got a moniter, printer, mouse, keyboard, speakers, CD-ROM, CD burner, Floppy drive and 512mb ram already.
I realize that this pretty much a dream, but w/e. Any ideas are welcome. :ear: