steamcleaner.tikione.org/en/ The good old time:
When you installed a video game from a CD or a DVD, you installed some redistributable packages too: DirectX, Games For Windows Live Redist, VC Redist, Rapture3D, NVidia PhysX Redist, etc. They were installed from the CD/DVD, and those installers didn't stay on your hard drive.
Now, Steam, the problem:
The Steam application allows you to download games from the Internet and install them, but what about these redistributable packages ? You probably saw they are installed the first time you launch your game, OK, but what happens to these files when they go wasted ? The answer is very simple: Steam doesn't delete them. An example: install the first complete season of Sam & Max (6 episodes): every episode is about ~300MB. For each of them, you can count 100MB for the DirectX redistributable package. Yes, it is about a third of the game files size, and they are not removed by Steam. For 6 episodes, you could save 600MB. Imagine what you could save for 10 or 20 games.
The solution:
A little tool that is able to list every redistributable package stored on your Steam directories, and allows you to remove them. This is the goal of TikiOne-Steam-Cleaner. This is a very simple program: set the Steam SteamApps folder (this is a sub-folder of the Steam application), click "Search", you choose what file or folder you want to remove.