I'm a sucker for stories with relationships that are actually poly or can be read as poly (like love triangles/polygons that are never definitely decided). Powerful Opponents, for example, or Black & White, where they kind of tie off the relationships but don't hammer the point. (I should mention that I don't mind spoilers at all, since you may have to spoil the relationship plot to rec.)

I also prefer stories with at least one primary female character and ones where the characters have ambitions and jobs that they love as well as romances. Saving the World never hurts, either.