I found myself wondering about this suddenly. I don't see it much outside of Sailor Moon crosses (for an obvious reason, since every senshi is technically a princess, or he was a prince and has the curse), so I was wondering if anyone knew of any stories where Ranma exercises the role of a princess or queen. I'm more interested in Ranma acting the part than being one in name only and taking advantage of her authority when it suits her. In the case of a Sailor Moon cross, it has to be Ranma (not whoever his/her past self was). The ideal story is one where Ranma's in a castle and rules over subjects, though plenty of people recognizing and treating her like a princess or queen is probably the best that I can expect to hope for.
There's no need to mention Ozzallos. ;p And I think there's one story (series) by Narsil that might apply, but I didn't read enough of it to remember whether it does or not.