I like watching the two Trekkies movies -- the second one shows slightly more normal fans, the guy who made his apartment into a Voyager enclave notwithstanding. They're like...convention substitutes for me. (If you only experienced the extreme parts of conventions, I suppose.)
I have both of the other Trekkies. Back in the mid 1990's there were plenty of Star Trek conventions to go to, and today there are none in my area. When I watch Trekkies it almost makes me feel like the convention is in my home.