http://esgameservers.com/freepcgames.html
The two games that I'm most interested in are:
Cube and Cube2
Free single and multi player 1st person shooter game with some satisfying fast oldskool gameplay. A large variety of gameplay modes from classic SP to fast 1 on 1 MP and objective based teamplay, with a great variety of original maps to play on.
Level editing has never been so much fun: a press of a key allows you to modify the geometry / textures / entities in-game, on the fly. Even more novel, you can make maps together with others online, in the unique "coop edit" mode (!)
http://www.cubeengine.com/index.php4
Battle for Wesnoth
The Battle for Wesnoth is a free, turn-based strategy game with a fantasy theme. Fight a desperate battle to reclaim the throne of Wesnoth, or take hand in any number of other adventures…
http://www.wesnoth.org/
