Hi Boot_WB,
I have an Intel 3 GHz Alienware. This machine runs XP Pro, is uberPOWERFUL and rock solid. I have had it for about 9 months and it has never once crashed on me. I regularly leave it on for days at a time and can run loads of programs at once (watching a DVD while using a P2P proggy, having a MMORPG macroing away in the background and moving files onto my A4000 hard drive via WinUAE is quite common :-D).
I'd imagine if you are feeling liquid cash-wise then an Alienware laptop would be ideal for 3Dwork or anything else (such as running HL2 at maximum specs - very important) that you care to throw at it. These machines are expensive but then quality always is :-)