Well, if it's base forms only, id say Necrozma. It's a great design imo and while I love base Kyurem, Necrozma just slightly eeks it out. Don't know how I feel about the mono-Psychic...
But if you wanna count the fusion forms, I'd definitely say Kyurem. They're just. straight up beautiful designs. I still think they should be Fire/Ice and Electric/Ice, but oh well...
On the topic, BW Remakes or B3W3?