There were quite a few different movies that I watched in school growing up, and I can't remember most of them. A lot of them were movies I'd seen before (some of them many, many times), but there were also quite a few I'd probably never have seen if I'd never watched them in school. When you have a class of students you're obviously going to have a group of people with a wide variety of tastes in movies, so I've watched quite a few movies I definitely did not want to watch. (I wouldn't have seen half of the sports movies I have if it weren't for school. I'd never seen Coach Carter before starting high school, but by the time I graduated, I'd seen it at least five times.)
There were two movies that I watched in high school that I never would have watched otherwise, but I ended up absolutely loving. The first one was The Prestige. We watched it in my sophomore chemistry class for some reason. (I can't remember why she let us watch a movie...) I thought I was going to absolutely hate it at first. It didn't sound like something I would like at all, but I'd now consider it one of my favorite movies. I loved it.
During my junior year we watched Schindler's List while studying the Holocaust and World War II in U.S. history. (I remember everyone being excited about watching an R rated movie in school when we were taking the permission slips home.) I wasn't as worried about liking this one as I had been The Prestige, but I didn't think I'd enjoy it as much as I did. As much as I love history, I'm not a war movie person, and a movie about the Holocaust didn't seem like it would be much better. That movie is amazing though. I feel like it's a movie everyone should watch. I'm pretty sure everyone in my class loved it. My sister's taking AP U.S. history this year, and I really hope they get to watch it. I took the AP class last year, and we didn't get to watch it because of lack of time, so who knows. (My school only started offering AP U.S. history last year, so I hadn't had the opportunity to take it junior year.)