Really funny Left 4 Dead parody, uses audio files in the game in a veeeery interesting way. Give it a listen! http://www.youtube.com/watch?v=NW8tE93Vx8Q
this is just like the "Heavy fucks medic" TF2 soundbite. pretty funny stuff, and i think Valve knows what they're doing when they make voice-overs for that kinda stuff. got a lol or two.