As someone who loves all sorts of music, I cringe when I hear that clichéd baritone sax thing during a "sex scene".
Seriously though, I'm guessing that there's no one answer, maybe depending on the mood, or the setting, or other factors?
I know, for instance, that my partner, Sarah can't get enough of these two examples, when she's in the mood for some romance: and yeah, okay, there is a saxaphone but, come on, Candy Dulfer; such a classy lady and a great saxophonist.