TP to the OP for this topic. I had fun thinking about it my whole ride home from work. I couldn't land on one leader but there are a few movies I'd put on this list.
Obscure/Not highly regarded movies
Fear of a Black Hat - a mockumentary about an up and coming rap group NWH ("****s With Hats"). I probably have watched this movie about 30 times. A group of about 6 - 8 of my friends love it, and quotes from it still get thrown around at parties, fantasy football drafts, etc. Anyone else around has no idea what we are talking about.
The Great White Hype - not very highly regarded in it's day, this movie has always cracked me up and I think it is one of Samuel L. Jackson's best roles.
Mating Habits of the Earthbound Human - movie features Carmen Electra and some random nobody guy actor progressing throw a relationship from dating to pregnancy, but the story is told from the perspective of an alien National Geographic Show.
Movies a lot of people probably wouldn't think I'd love watching over and over
Lost in Translation - I absolutely love this movie, and can pretty much pick it up at any point in the story and keep watching it. ScarJo was young and super hot, and there is something about the story that just resonates with me. I also think the ending is perfect. (spoiler alert) A few of my female friends have vehemently disagreed with me on this, but I like not knowing what they said to each other. I love that it is left to the imagination. I was just happy that in the end the elephant in the room was acknowledged, and they had the "moment" they both wanted instead of it ending with a great "what-if".
The Princess Bride - just a fun movie to watch, even years after my childhood when I first saw it. A light, entertaining chick flick that this guy can watch over and over again.