68159
Never got the draw to Halo; though with me shockingly getting to like FPS games now(Mostly because of gaming on the PC... Could there be a shocking connection? =O), maybe I should try to give the series a shot... Though, well, there's the whole 'I don't have an Xbox, and don't plan on getting one' problem. =P
68163
The PC version of the first Halo is pretty rockin' (Like 5X better than the Xbox version) but it's not sold anywhere anymore so you will have to acquire it through *less than legitimate* means (that said though A++ would legitimately purchase)
Halo 2 has a bad PC version
And none of the others have PC versions
I haven't played any beyond one because a. I don't own an Xbox and b. twin analogue FPSes are always bad