For general feedback about the game.Steam Support
Visit the support site for any issues you may be having with the game or Steam.
After setting a new standard for Lack of Class in an FPS with the addition of Jarate (the jar-based Karate), we've raised the bar on lowering the tone even further with the first ever Classless Update!
Also, if you haven't seen them yet, ubercharged.net is currently up to part three in a nine-part series covering how each TF2 class is used in competitive matches. It's a fantastic read if you want to get some insight into the strategies of TF2's most skilled players.