Book where MC ends up with someone unexpected but it actually makes a lot of sense?

Are there any books where it looks like the MC is gonna end up with Person A but actually ends up with Person B, however this isn't a bad thing b/c Person B and the MC had a lot of chemistry and actually work really well together? It's doesn't have to be a straight romance, and I don't mind the general setting (modern, period, fantasy, etc) but I'd prefer if there's little to no spice!! Some other turn offs I have would be miscommunication and heavy angst. Thank you!!