5. Pulp Fiction (1994) - Quentin Tarantino/Roger Avary
There are some screenwriting professionals out there who would tell you to avoid
Pulp Fiction at all costs as benchmark for "good writing." After all, it follows absolutely none of the traditional screenwriting methods or rules that any right-minded tutor or book would tell you: instead, it clings to a hip, post-modern structure, and skims almost completely on the emotional front. But to hell with those guys, because
Pulp Fiction is an awesome screenwriting feat - so much so, in fact, that it changed movies forever. Tarantino pretty much re-wrote the screenwriting rulebook for this one, and although I'd recommend that absolutely nobody ever try to "write like Tarantino" (everybody starts out doing that, don't worry - movie executives hate it), this script is pretty much required reading for anybody who wants to hone their dialogue. Most people watch
Pulp Fiction and come out with the opinion that Tarantino writes "realistic" dialogue, though it's far from it. The man's genius is in just how he convinces you that what you're hearing sounds like everyday conversation. You can read Quentin Tarantino and Roger Avary's screenplay
Pulp Fiction here.