Well wouldn't you just know it. I went to some effort to acquire a number of games, and work out the L4D2 split-screen fix, and what happened.... we played Fifa 2012 from 10pm to 5am over Friday night and kinda burnt ourselves out and didn't play anything else. I shoulda known really, it's kind of typical of when we get together.
I have outcomes like this with my coop chum; set up all these new games and end up installing one older game that we've already clocked hundreds of hours over.
TrackMania Nations is great for local 2 player with it's party mode. The Worms games are great too. DiRT games support 2 player if you can get 2 controllers. If you can get 2 Xbox controllers (doesn't work with any others), then you could play split-screen Blur.