People fall in love with their best friends in real life all the time, and it happens a lot on the big screen too. Harry and Sally found that it's hard for men and women to be friends at all, while a couple of modern romantic comedies have shown us that it's tough to be just friends with benefits. Sometimes the sweetest love stories are ones that start with a friendship. In honor of Valentine's Day, check out the best movies where the onscreen buddies go from platonic to romantic.
—Additional reporting by Shannon Vestal Robson, Maggie Pehanick, and Kelsie Gibson