Command & Conquer For Free!
EA is celebrating the 12th birthday of the first Command & Conquer game by offering it as a free download. The version offered is the Windows 95-compatible "gold edition" and comes on the GDI and Nod discs. There are install instructions as well as it seems there are some extra steps necessary to get it running under Windows XP.
Apparently the game runs on Wine as well but not on Vista (thanks 0bsolete).