I am doing (have already done at a party this past Saturday) Ben Franklin, because I like to do historical figures I admire and/or find interesting. My wife is doing (did) a Spirit of Fall autumn tree queen outfit, and my three year old wee boy will be (was) Elmo from Sesame Street (his hero). I never do kilt/Highland dress things for Hallowe'en because for me the kilt is both a traditional and contemporary form of national dress, and definitely not a costume.