I don't much care for surface piercings in part because, as has been said, they tend to be red and irritated, and not to last; and I just find them artificial and mechanical against lovely female skin. Back corsets are really sexy looking though, but of course have the same problems as other surface piercings.
And I find lots of facial piercings both to be unattractive for similar reasons of providing the wrong sort of contrast for the beautiful lines of a woman's face, and also very importantly to get in the way of physical contact. Though pierced nostrils are pretty and sexy, whether studs or rings.
Multiple and unconventional earring piercings can be quite attractive when not too large or overdone.
I do find thick - but not too large diameter - nipple rings to be very sexy. Thick rings are also more inviting to play with, because they spread force out better in sensitive tissues than "cheese cutter" thickness rings, and so they're more likely to cause pleasure than pain. Barbells are OK, and I'm always glad to offer to swap them out for some nice rings at playtime.....
Navel piercings are very attractive to me. Though some of the really big jewelry pieces for them over-do it, in my opinion.
Genital piercings, as long as they're not excessive, are also really pretty and a real turn-on, both in the clit hood and the labia. I think the various hood piercings are particularly great for women who actually get needed additional stimulation from them. As with nipple jewelry, I like to see them thick so they have a real visual effect.
I can't imagine anything sexier than playing with some nipple rings, and getting glimpses of a woman's genital jewelry as my own piercings slide against the sensitive spots inside her.....
I also admire tattoos that are artfully done, which generally means not too many or too big, though some larger pieces are real works of art.
I'm surprised to see so many negative comments from men. I hope that's not representative. What do women think of men's piercings?
All in all, I think can be very attractive if a woman has made a canvas (or bodyart installation) of her body, and can inspire a man....
FF