I absolutely love L4D. I play it on 360 right now, but when I get my new comp, I'll get it again for PC as well.  The versus mode is ridiculously fun and the campaigns are never quite the same, so playing it on a harder difficulty is actually always a challenge.  It is most fun with only friends because you know they'll all work as a team. Oftentimes, I get stuck with someone who has no mic or is just a douche or maybe has no idea how to play, and that can suck out some of the fun for me.  Regardless, L4D on the PC is a great buy because Valve is already working on releasing some new campaigns. Not to mention the fact that the fan base has been asked to make their own maps.  This is easily my favorite game on the 360, so I am sure it'll be just as great on the PC too!

Get it!!