Team Fortress 2 works pretty well for me, as well as a bunch of other games that use Source engine.

I recommend you to use plain Wine without PlayOnLinux. Winetricks is helpful, however.

Steam Games on Linux website has detailed information about which games can be played successfully, and what you have to do for that.

Team Fortress 2 on that website (Status: playable)

• First you have to Install the latest Wine.


• Make sure to configure Wine (look at STEAM + WINE CONFIGURATION section)
  
  How to use Winetricks:
  
  
  
  • Select the default wineprefix OK
  
  
  • Install a Windows DLL or component OK
  
  
  • It is important to mark d3dx9 here. Optional packages that may be needed for some games: d3dx10, vb6run, vcrun2005, vcrun2008, vcrun2010, physx. OK
  
  
  • Install a font OK
  
  
  • Mark corefonts and tahoma. OK
  
  


• Next, download Steam and go through the installer.


• When you create an account or just log in, you should have no trouble downloading Team Fortress 2 through Steam and playing it.


• Make sure to change video settings in the game to lowest ASAP (don't miss the "advanced" video settings). Windowed mode is mostly better. It is good to restart the game after this.