I got a link to some cool free games at BinaryZoo, very fun and addictive. I liked Mono the most, it’s like Asteroids on acid and speed. Reminds me of old school arcade machines (1 or 2 Kr. per play) and some of the Amiga classics. Quick and no-brainer games for instant fun in the wintertime.
If you have a modern computer and some spare time, X3 – Reunion is my current favourite. I spent many hours playing the prequels X – BTF and X2 – The threat when they came out years ago, and so far the hours have gone quickly while playing X3.
X3 is a realtime space game, where you play a pilot building an empire by trading, fighting, exploring and building in a huge universe. If you have played the games Elite or Freelancer you get the idea. X3 was buggy and crashed frequently at first, but download the version 1.3 patch and everything works fine. You do need a good 3D card and lots of memory for the game to run.