EDuke32 is a Duke Nukem 3D port that adds several hundred new features for players and developers of user content, including hardware accelerated renderers that take advantage of modern graphical hardware.
Zatacka X is a modern, free remake of the classic Achtung, die Kurve!. In addition to all the features from the original game, it includes special weapons, sound effects, AI controlled opponents, a tournament mode, and possibly online play.
HoldingNuts is a multi-platform poker client and server. You can play the popular Texas Hold'em variant with people all over the world, meet your friends, run your own games, and even set up your own poker network.