I was ar Disney for Halloween time last year which is AMAZING for the costumes (adults can wear costumes during the special event of the Halloween Party and I believe on Halloween itself). Well, the best costumes to me were the more obscure ones. Example: my favorite was the couple dressed as Merlin & Madame Mim from the Sword in the Stone... Only it was the Merlin in the swim shorts after he returned from Bermuda and the sexy version of Madame Mim.

Years ago a guy was dressed as Quail Man from the kids TV show Doug. OMG it was pretty epic especially when he told me I was the only one (at that point) to recognize his costume.

On women I like sexy costumes that aren't too revealing: catsuits especially!