I just found this awesome Movie some fan's did, it's really good, but right now it's only 2 part's they continue on doing it :DDD
Left 4 Dead - The Movie (Part 1) (http://www.youtube.com/watch?v=_Q42t95cCIk#ws)
Left 4 Dead - The Movie (Part 2) (http://www.youtube.com/watch?v=sEnMN02d1E8#ws)
I must say I liked part 2 way more then 1.
I liked it thought it was pretty cool.
Slo-mo bit was awesome ;D