Ugliest : Volca Samples OK GO Edition, Novation K-Station
Most beautiful : Lyra-8 in Pink or White, Minimoog Model D and Voyager, Moog One and of course the Elektron boxes. Mention to the Colourful Moog Series (Sirin, Grandmother, Matriarch) and Novation Peak.
Edit : I forgot the new MS-20 in white. A beauty.
Pics for weird choice if you want.