i havent owned any, but ive played with some. falcon, imo is the best of the bunch. alienware is way too expensive for what you get. falcon is high but at least they have some killer rigs (one of the few places that offers raid). wolop is probably the best priced. they are still way too expensive though.
i nearly crapped when i saw an alienware 1.0 ghz p3, 128 megs of rdram, and no monitor for $1700. how f'ing insane is that?