If price is an issue just go with the cheapest one. Avoid any P4 celerons though as DaveSimmons hit the nail; I just got a notebook based on the Celeron M 380 because cost was my biggest factor and it works fine. I haven't done any gaming, nor do I plan to, but when I tossed an extra gig of ram to bump it to 1.25gigs everything became silky smooth insofar as having a thousand windows open 🙂
If you aren't interested in gaming or doing heavy simulations, I would probably look at cost being the main factor, unless the build quality is simply shoddy...but if you were really inerested in gaming, I doubt the processor would hold you back as much as the videocard and you simply don't see a 6800Go paired up with any "lower tier" processor