Well I'm moments away from losing my last name, so right now my dream surname is simply to be able to keep mine!
Besides that I would just pick names farther up my family tree. Bouvier, Lefebvre, Delacour, Belanger, etc. are some favorites.
Of course there's a few celebrities surnames I'd like to have too but that has less to do with how they sound... Attachment 1382
I would love to be a Wilde.