1. 123 Free Solitaire - solitaire games collection

http://www.123freesolitaire.com/

2. Arcade Pack - classic arcade games

http://www.neowin.net/forum/index.php?showtopic=471360

3. Live For Speed - online racing simulator

http://www.liveforspeed.net/

4. Enigma - puzzle game

http://www.nongnu.org/enigma/

5. Freeciv - multiplayer strategy game

http://www.freeciv.org/index.php/Freeciv

6. Tux Racer - race down steep, snow-covered mountains

http://tuxracer.sourceforge.net/

7. Toribash

http://www.toribash.com/

8. OpenBve

http://trainsimframework.org/

9. Scorched3D

http://www.scorched3d.co.uk/

10. Alien Arena

http://red.planetarena.org/

11. Glest

http://glest.org/en/index.php

12. Rigs of Rods 

http://www.rigsofrods.com/

13. Singularity

http://www.emhsoft.com/singularity/

14. Heroes of Newerth

http://www.heroesofnewerth.com/

15. Bos Wars

http://www.boswars.org/