I heard 2012 was awesomely horrible.
I just hope the year won’t be.
If everything does go down like that this year, I’m driving up to the movie theater I saw the movie at to heckle our last days with that great crowd.
It’s close enough to the theme of this thread for me to mention one of the most hilarious moments in recent (?) times I was privy to.
My wife and I were in a neighborhood theater watching a rerun of Live and Let Die (1973) when it came to the scene where Roger Moore walks across a group of gators from a little island he was on to the mainland. About halfway across, this little old lady sitting behind us and to the side (well enough that we could see her) just muttered, “Shit!” We were laughing about that well after we had left the movie.
Incidental note: the man performing that stunt was Ross Kananga, who owned the alligator farm where that scene was shot. During location scouting, the crew found the farm and its “Trespassers will be eaten” sign and liked it so much that they wrote the sequence into the movie and named the villain Kananga.
Excellent, Bryan Ekers! I’m glad not to be alone in appreciating that sequence. Wish I could find that little old lady. 
Drag Me To Hell was great fun with a rowdy audience. There are a lot of gross-out scenes and jump-scares and the sense of participation we were all feeling really added to the experience. During the goat scene, everybody lost it and it was one of the best laughs I’ve had in a theater in a long time.
I haven’t seen the movie since then, but I suspect it wouldn’t be as good without that audience participation aspect.
Another vote for Rocky Horror. What fun. 25 years ago, a whole bunch of us cast members from my community theater attended a midnite screening after our evening performance of ‘Wonderful Town’ - dressed in full 1940s-era regalia complete with hats, veils, gloves, snoods, zoot suits - the works.
The funny thing is, we didn’t stand out a bit. 
Dang it, missed the edit window.
Almost forgot about Poltergeist. THAT was a rowdy bunch. My favorite was when JoBeth Williams was lurching down the hallway (which was doing that weird camera trick where the hallway gets longer and longer and she’s still lurching) towards the closed door of The Bedroom of Doom, when some guy down front of me leaps and hollers at the top of his lungs, “DON’T DO IT, LADY!!!” The whole place fell down laughing.
I saw “Friday” in the theater for the first time with a bunch of high and drunk people (well, I assue they were drunk and high-- I was), and it was crazy-- awesome, but crazy. I love this movie regardless of the rowdy audience, but the audience reactions really enhanced the experience.
Just a little while ago I had the opportunity (in another thread) to refer to the “Never mind the mules…” thing and it made me curious if that expression had meaning to others on the internet. Among the hits I got on a Yahoo! search was Hilarious putdowns of iconic movie moments which had 82 replies between 02-22-2009 and 02-27-2009, and which I almost bumped to see if it could get more recent replies. On second thought I chose to link to it here, since it’s basically the same issue/theme.
Back in the 70s, I left my friends and wandered around Mexico City one night, just to see what I could see…
Ended up at a kung-fu movie. Since it was subtitled, the audience could yell all they wanted at the characters on screen, and at each other, without missing anything.
Fun was had.