The following movies are a short clips of playable classes in Team Fortress which I found on the Steam site:
The Sniper – http://www.steampowered.com/v/index.php?area=app&AppId=5051
The Scout – http://www.steampowered.com/v/index.php?area=app&AppId=5032
The Heavy – http://www.steampowered.com/v/index.php?area=game&AppId=960
The Solider – http://www.steampowered.com/v/index.php?area=game&AppId=985
The Demoman – http://www.steampowered.com/v/index.php?area=game&AppId=997
The Engineer – http://www.steampowered.com/v/index.php?area=game&AppId=987
Just the Spy, Medic & Pyro to go!
As I have said before on this blog, I usually hang around the Game Arena servers under the alias ShadowXVII when playing Team Fortress.