Guys: Which would you rather your girl wear? Which do you think is more attractive?
Girls: Which do you prefer to wear?
My answer: I like to wear one pieces in public because I feel that my body isn't for random people's eyes. I have a nice figure, but my boobs are a bit big for a bikini top to supply enough coverage. When I'm at a private pool or on a boat with just girls or a boyfriend, I don't mind so much wearing bikinis.
I personally find it very appealing when a woman wears a bikini and prefer it over a one piece since I find a woman's midsection is attractive.
I however have come to the realization that a woman in a once piece can be just as desirable because of how much the garment covers, adding an air of mystery. Though if you want to keep your body private for that someone special I completely support you, I feel there's a kind of romance behind it. :)