Anime with romance as a main or relevant part of the plot, but also a "bigger plot" going on.
I'm talking actual romance, more than just "two characters happen to like each other". Something that is relevant, and ideally progresses through the show (note: also includes some incomplete adaptations with more romance past anime content).
As for the bigger plot, it can be anything from fantasy, adventure, mystery, sci-fi, etc. Check my notes for details.
Harem are mostly ignored as they are usually lacking in actual romantic progress, unless there is a clear main love interest.