I used to own an Alienware laptop. I will never, EVER own an Alienware product ever again. I was appalled by their service (but then, it's Dell, so what was I thinking?), burnt by their prices, singed by their overheating components, and disgusted that I couldn't play anything without the whole system shutting down from overheating. I'm sure they've gotten a lot better by now as far as components go, but when it comes to service, Dell is not to be trusted.
I have, on the other hand, found TREMENDOUS success with ASUS's line of gaming laptops. I build my systems, but my sister's gotten an ASUS gaming laptop twice now, and we've been phenomenally pleased. Hitting the sub-$1K price point and still getting an exceedingly entertaining, top-quality system was a simple affair.