There was a spat of these "unpopular guy gets popular girl" films in the 80s, like Patrick Dempsey's Can't Buy Me Love and Eric Stoltz in the one with Amanda Jones...Oh, Some Kind of Wonderful. Essentially, they all run something like this: unpopular or unknown guy gets super hot girl, who discovers that he's way better than the dumb jocks she's been dating.
But Say Anything is somewhat different because it's not that Lloyd is unpopular, it's just that he's not in her league. He's older, and has no plans for college. He lives with his sister, his parents are nowhere to be found, and he likes to kick box. Diane is the one with the future and the plans and the brains. They have this great kiss in the rain where he's super tall and they're both soaking wet and he's got his hands tangled in her hair and then there's this other sweet moment right after the first time he sleeps with her that he's shaking but denying it, but still shaking and he says it's because he's happy.
Of course, there's also the fact that he keeps saving her, kind of, making sure she's safe at the party, that she doesn't step on glass on the sidewalk, that she can travel to London without freaking out on the plane, and he's this replacement dad figure, because, in an unexpected and possibly unnecessary plot twist, Diane's dad (played by the guy who was Frasier's dad in the show) turns out to be a crook, embezzling from his elderly clientele. And still. And still, it has this amazing Lily Taylor as his best friend who writes countless songs about her ex boyfriend, and who rejects him when he wants to get back together and she doesn't end up with someone else and that's okay and there is not sexual tension between her and him, and that's okay too, they're friends and she thinks he's amazing and that's it.
Then again, is it stalking to leave eight voice messages and stand outside a girl's window blasting Peter Gabriel's "In Your Eyes?" Naw, it's not too bad. "I gave her my heart, she gave me a pen."