Personally, The Rocky Horror Picture Show.
I knew it was going to be quite the experience before I went for the first time‡ but it was so much fun I had to keep going back bringing friends each time.
It's still a fun tradition to do though we haven't done it since last year, we're probably going to try and go again in a few weeks.
‡ I had seen it many times before going to see it in theaters for the first time.
I went to see the original Avatar movie 3 times. First time I unknowingly watched it in 2D. Then I thought “this would be amazing in 3D”. Then I saw it in 3D and it was so fantastic that, a few weeks later, I watched in 3D again. No regerts.
Hey, came here to say the same thing. Watched it once in 2D and two times more in 3D. Awesome experience!
I wish 3D had stuck around long enough to get a 4k HDR 3D release of it. Ah well, maybe 3D movies will come back again in another 20 years with higher framerates and better displays.
Ain’t gonna happen because there is no such thing as 4K 3D in Home Cinema terms, because unfortunately 4K UHD Blu-ray’s don’t even support 3D. It’s not in the spec. But yeah, I hope 3D will come back in a few years with much better specs.