The community. The people. MC was the first truly friendly forum I had ever been a part of, and as such, it helped coax me out of my shell, because there were so many wonderful, kind, and friendly people here who thrived on making this place fan and enjoyable for everybody. Prior to MC, I had really only belonged to maybe three forums, two of which were really small and dedicated to just one show each, so there really wasn't much a community at either place; the other was the ToonZone forum, and the people there seem to strive to make other people feel like crap as much as possible, and I was always treated like a village idiot over there.
MC, however, has been a wonderful community to be a part of. As I've said many times before, even though I first joined in 2003, it really wasn't until 2005 that this place really began to thrive, and that's mostly attributed to That Announcer (wherever he is): he really got the joint jumpin', and as such, more and more of us were coming out of the woodwork and actually participating among the forum outside of just standard discussions of movies, shows, other Henson works, etc. We actually started interacting with each other and developing friendships and connections among the community.
As many have said before, MC is more than just a message forum, and it's more than just an online community, we really are like one, big, dysfunctional cyber family. That's something that I really appreciate about MC and that's really what keeps me coming back: in all honesty, I feel a lot closer to most of the people here than I do to most of the people I know in real life; you guys have been a great source of support for anything I've gone through over the years, and as somebody once pointed out years ago (I forget who), you guys have literally seen me grow up here - I was just fourteen when I joined, and I'm twenty-seven now . . . that's a long time to dedicate to a place like this.