Biomix,
did they do the same things at the one you went to?

I was actually surprised that the singing seemed kind of quiet. perhaps it was due to the number of new people like myself. there appeared to be more yelling at the screen and physical interactions (dancing, blowing bubbles, waving light sticks), than singing if that makes sense.

I also discovered that who you end up sitting near makes a difference in your experience. If you're around people who participate, you're more likely to feel comfortable doing so. Though if you're around people who participate too much it can be a bit tiresome.

I had a really nice guy next to me that had never been before either so we kind of kept each other from feeling too out of it. and this very flamboyant man next to him that was clearly a regular and quite fun because he would jump up and dance and such. however, directly behind me were two girls that sounded like teenagers and yelled so incessantly that I actually couldn't hear some of the dialog/music. I mean yelled teen stuff "like OMG he's soooooo hot" (sounding like she was going to wet her pants) and "shutupdawnshutupdawnshutupdawnshutupdawn" long after everyone else had stopped. So it quickly grew annoying. The crowd was more thick towards the front, so I imagine that would be a very different experience than where I was near the back.

If you go, pay the $3 for the buffy goody bag so you have props for the interactions. it'll be more fun. then next time you can bring your own if you want. :) Mostly, I think one of the big benefits to going is that it's a socially acceptable environment in which to yell loudly. ;)