Team Fortress 2 (official)
The official site for all things Team Fortress 2 and Team Fortress Classic.

PlanetFortress
News, Maps, Info, Screenshots, ect. The true Team Fortress Network.

TF2.com
Team Fortress 2 stuff. (Cool Shockwave site)

The Ladies or Team Fortress
Calling all Ladies out there that play Quake, TF, or TFC. This site is made for you. Check it out for yourself.

The CLQ
Find most anyone who plays Half-Life (or most mods of HL), Quake, Tribes, or Kingpin. You can see rankings of players or clans. Really cool site that tells you how you're doing among all the players in the World!

Half-Life Map Domain
  This is a map review site for HL single player, TFC, and TF2.