whitelight1 linked to your post and as for CSI: I suppose you could call it a big fandom, in that it's the #1 show in America or some such jazz, but...it doesn't quite feel as "big" as Farscape did. (does?) Its main archive is ff.net, which is the devil, though there are smaller specialized archives for pairings. It hasn't got much of a community in that it's incredibly factionalized. So while on paper it would fit a lot of the requirements, I just don't get that vibe.