It came before Please Teacher, before Love Hina, even before Kimagure Orange Road. I might be too young to say for sure, but I'll bet this is the series that started the whole romantic comedy movement. It's also one of the few with a mature enough storyline to keep post-teenagers interested.
Yeah, it's the same plot that exists in every anime of the type: boy meets girl, boy and girl deny their feelings for the entire series (but hook up every few episodes), boy and girl finally get together in the end. As a consequence, the plot moves a bit slowly and is a bit too one-track-minded; more fun plot diversions would have been welcome. Still, it's a pretty funny series, and the characters are colorful enough to care about for 96 straight episodes. If you're into Rumiko Takahashi's stuff, Maison Ikkoku's probably the best place to start.