This morning I saw this on Steam.
You can now get X-Com for $5. Probably one of the more reliable ways to get a game this old, so I thought I'd point it out incase anyone is looking for it.
Edit: Just realized someone pointed this out, oh well.
@'Guest': X-Com dosen't have a download on this site, nor is this site crappy, what are you talking about? Sorry if you were looking for a warez site friend.