Hey
I think its great that you can play in splitscreen mode, in Left 4 Dead with a friend on the same computer.
I have a wireless Xbox 360 PC controller, so L4D in splitscreen on a TV = awsomeness
Video guide: http://www.youtube.com/watch?v=9QRrpqm0VzU (Have not tryed it yet)
This guide can be followed: http://forums.steampowered.com/forums/s ... p?t=745113 (Have not tryed it yet)
And more splitscreen games here: http://pcsplitscreen.freehostia.com/ and guides.
Enjoy!
From Kehaan.