Look no further, after using my Dell XPS M170 I've come to realize how much of a bad ass system it truely is.
I've seen similar systems which try to compete, but they're heavy, and loaded with hot desktop processors, like the alienware; which tends to get so hot that it can fry the motherboard or cpu.
Granted, I spent a few extra bucks pimping it out with more ram, and a faster pentium M processor. Some of the newer systems have the Duo processor which is great for multimedia apps.
I've run every game that's a resource hog that you can image, and every bit of it flows smoothly. This notebook stays ultra cool, and I've had at least 2 hours or more of battery life out of it.
I'm highly impressed with it, and it's deffinately an impressive portable gaming rig.
At one point I was considering purchasing an Alienware, or a Toshiba, but this is probably the best investment I've made.
So if you're looking for a notebook with kickass performance, check out Dell's latest XPS notebooks with Nvidia's 7800 GTX, or even Dell's multimedia E series machines with faster ram, and duel core processing power.
It's worth buying, if you're willing to spend a lot for a notebook.