For the longest time (my entire adolescence ... plus...), I considered the funniest movie ever. Then I watched it with a family friends of mine (father, mother, underage daughter). I was kind of embarassed. I had forgotten how gutter some of the humor was. I still remember the opening line:
The popcorn your eating has been pissed in, film at 11.
Everyone looked at me, hand full of popcorn in the air hovering uneaten in front of their faces. I blushed.