Stockings with garters are really hot.
Wearing a thong, if you ordinarily don't, can be very hot. I was in line behind a young woman wearing jeans at a store, and when she got to the counter she leaned forward for a moment, showing the straps of a thong just above her beltline. Incredibly hot.
Convenience crotches / French cut undies -- very hot. They say, "Not only am I teasing, but once the teasing is over I'm ready to seal the deal."
Bras that don't cover the nipples (or have detachable nipple covers) -- very hot.
In general, as you might be gathering, I like lingerie you can keep on while still having sex. This avoids one of the main problems with using lingerie to arouse -- the usual course, once aroused, is to get the barriers (i.e., lingerie) out of the way so that the arousal can be sated. But this can be somewhat self-defeating, since the thing that was so arousing in the first place (the lingerie) is now no longer in play.
Also, lingerie that fits a "character" or "skit" can be very effective if you're willing to do a little acting. (Women? Acting in a bedroom? I must be crazy to even suggest such a thing. :>)
Kevbo