There have been two movies I did this for. The first I can remember was Star Wars Episode 1, the second was Avatar.
Star wars was just cuz multiple people wanted to see it so I went a couple times. Avatar was just so awesome that I had to go see it again because I coudln't wait until it came out on Bluray. :'D
The only movie I saw twice in a theater would be Spiderman (2001) because I loved it. Otherwise I don't go to see movies twice anymore, nor do I buy them on DVD/BluRay. When there's finally a movie that I actually want to see, I just go to see it in the theater for the best experience. Simply because I find it boring watching the same one 2 or more times. Only for the ones that I was really impressed by will I buy on DVD, and so far this year the only case of that would be The Dark Knight Rises.