I prefer CS 1.6 to Source imo. Don't know how GO is going to play out, and wouldn't it be free on Steam rather than XBLA? Yes, gooslaps, the mods ruined CS now. Couple of months ago, I searched for matches on Steam and nearly every servers had mods...lame.
PC version is supposed to be getting a Beta. I only started play CS at the end of last year, i mainly just play gun game on CS:S but it's alot of fun. CS:GO is apparently having gun game as one of the playable modes.