I usually just play characters with their normal colors, but if I had to pick favorites: Dark Olimar, Dark Toon Link, and anything on Snake.
Normal skins usually. Even most of my Mii's are in normal outfits! The only exception is I always play as red and white R.O.B.
havent played smash in almost a year but i always Always pick an alt and i have a favorite for every character as well i do have the base template if anyone wants to make their own