Valve have created Expiration Date, a 15 minute animated short featuring all the Team Fortress characters.
Half-Life: Raise the Bar
Half-Life: Raise the Bar is a fan-made short film inspired by the Half-Life franchise.
Portal: Survive! is a live-action short film based on the Portal game, and its tie-in comic Portal 2: Lab Rat.
Team Fortress 2 - Meet the Medic
Team Fortress 2 is now free to play, and along with that great news, Valve have released a new cinematic, Meet the Medic.