Replying to Do you know of any downloadable, full PC games for free or cheap?

I am looking for a new game to play on my PC when I have some free time.
I have a fast PC and a good graphics card, so I might as well put it to use with some occasional 3D gaming.

A good 3D first-person shooter is always my preferred genre of PC game. But I am open to suggestions.

Anyone know of some good 3-D games I can download for free? or very cheap?

Or the other option- if you already have the files saved on your computer for a game, I would appreciate it if you could send me the files (depending on the game).
I could wire you like 5 bucks through Paypal if it is a full version of a good PC game. But free is always cool with me :)

Any help is much appreciated.
Thanks!

peace