Maybe bras and underwear since they're made specifically for the body shape. But honestly other clothes can be worn by the other gender because who cares. If you wanna wear something that's stereotyped for the opposite gender, then do it
I have to wonder, and wonder if I care!! The Scotts and several Asian nations traditionally wear kilts, or what Westerners would call 'skirts' but I wouldn't mess with them and call them 'sissies'! Underwear, well, it's really the cut and the kind, or color of the fabric that makes them 'Panties'. When it is really hot, I wish I could wear a skirt, and not have the legs of my pants sticking to me! Dresses are just single-piece skirts, and I'm jealous how comfortable women can be, wearing them, when it's hot!! Why do we care so much? I'm hoping that the 'Millenials' can change this, and challenge these old style types!!
Maybe like bras and panties just because of the anatomy involved. I'm not sure anything else really qualifies. We assign a lot of gender connotation to clothing but it's not like it's always been the way it is now and there's no reason to think it should be in the future. But as a guy, I can't imagine going around in public wearing a shirt and leggings and high heels lol.