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.
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.