Most Helpful Guy
I absolutely have an underwear preference! They should be OFF! (I'm only kind of kidding.)
But if you must be wearing them, then MY preference is that the are smooth, thin, and as seamless as possible. I want to see your shape. I hate seeing seams (bra cups mostly) and I really hate the lumpy look of lace, ribbons, and bows when they're under clothes (it's not so bad without the clothes, but I still prefer plainer, smoother designs). If you wore a string bikini as underwear, that would be ideal. Some of the VS stuff that has the ads that say something like "only your shape shows" is good too
Style doesn't matter to me too much; wear what works best for your body and/or whatever you're most comfortable in (that isn't granny panties). I don't really have a preference for thongs vs. biknis vs. boy shorts. At least one of those will look good on you, and most girls can wear any of them and look good.