Least favorite would probably be piebald because IMO white/pattern/white often breaks up the graceful lines of the snake in an unpleasant way, but that's not too say there aren't some really cool isolated patterns created, such as smiley-faced pumpkins, etc. Also, not a fan of anything with pink eyes, cinnamons, chocolates, or scale tones that look too faded-out, however I do like some carmels and butters.
Not thrilled about fancy 'paint jobs' just for the sake of being way-cool or very rare if it compromises the health of the animal. As many have pointed out, this seems to be the case with wobbly bees or when reinforcing some recessive genes that bring along serious health problems.
My overall favorites: Mojave, Enchi, and Pastels ... and really like plain-old Normals since Mother Nature does some beautiful work on her own!