As for the best laptop, I really do think that the best one in every sence is Apple's Powerbook. Since you want it PC compatible, its probably not what you looking for (This is actually the only one). But you can run OpenBSD, Linux, NetBSD and Darwin on it + (MacOS X is based on FreeBSD kinda) and you can have a virtual PC within MacOS X to run windows. Just Check the Apple's site for more info. The new ones come with 1Ghz G4 Motorola RISK PPC, which outputs 7.5 GFlops.