There are a lot of sub-genres in movies: spaghetti Westerns, Police Procedural Mysteries, and Epic Fantasy - like Lord of the Rings. You can usually find a lot of room within these sub-genres for imaginative examples. They can be wildly different. Romantic Comedies seem to have less leeway. You have a formula that is often used, with minor changes here and there. The characters usually seem to have little in common at first glance, one of the characters usually gets sidetracked by another love interest (in Fever Pitch the love interest is the Boston Red Sox), there is a breakup where one or bo...