I just came across this article: http://www.movoto.com/blog/novelty-real-estate/princess-peachs-castle/ which estimates that Princess Peach's castle in Super Mario 64 is worth $950,972,640 (presumably in American dollars). In case money factors in to the decision.

I think it's worth noting that Daisy gets kidnapped considerably less often.

Daisy

Be kidnapped every week or be a troll and a possible molester?

The "molester" thing is pure spontaneous fanon, not supported by anything in the show itself. And she's not a troll, she's a prankster. Big difference.

Seems like a pretty obvious choice to me. Peach has, as pointed out, the downside of the kidnappings. Other points to consider are that she's human and she rules a kingdom of useless mushroom people. Her main suitors appear to be a plumber and a giant dinosaur turtle thing.

Celestia is an immortal sun-goddess, she can fly, she has telekinesis, she can teleport and probably perform many other spells we haven't seen yet (she teaches magic after all), and she rules a prosperous country of ponies that also have tons of magic of their own.

I'm a guy...

Not any more