I'm surprized The Ur-Quan Masters isnt up there. Its a re-code of the original
Star Control 2 (abandonware) for PC made 10 or so years back. The original source code was lost, but the 3DO code remained intact. So they recoded to work on windows. The music is different, they added the voices (only in 3DO version), but besides a few bugs on certain systems and OS's, it works perfectly, besides being in a beta stage.
Great, complete game. Also very large, with a lot to do, and fun without a walkthrough (albeit hard).
sc2.sourceforce.net