Left 4 Dead and Saw will probably be the next games I get. I agree with Doc on this. If I get a bunch of games I'll never find time to play and finish them all.
Take their advice, I bought 6 to start with and gave them all about 2-3 hours tops and couldn't really get into 1 of them with enough time to tell how they were.....My favorite are still the multi-flavored slurpees..