For me it's kimonos. I kind of understand that the appeal comes from a woman wearing something so conservative that it should be titillating when she's removed from them and see what's under all the cloth, but it just doesn't for me. I feel it's because they hide too much of the woman's shape and skin. Even if they hide big breasts under them, there's not much preview with regards to how they look, compared to maid outfits or office attire, to name a few.