Missing textures and models

Do I really have to buy like 5 other games to get all the textures and models? Because I REALLY don’t think that is what everyone else is doing. And I’m sick of staring at “ERROR” signs left to wonder what I should be seeing.

Is there anyway I can get this stuff off the web? I don’t want to buy 5 potentially horrible games I will never play for $150 just to play Garry’s mod. I currently only have Team Fortress 2.

[editline]4th June 2012[/editline]

Nevermind, found CS:S source files, seems to be a majority of stuff I’m missing.