Its a mix up between Divine Soul and Wild Magic, but I'm going to have to go with Divine. Its the only sorcerous option that I feel actually makes your Sorcerer do different things and have features that actually go concurrent with the character your building. I've played every other Sorcerer at this point aside from the Shadow, and I've always felt that regardless of the Sub-Class, every sorcerer felt the same overall, and that isn't something I get from any other class in this game.
Draconic. While it may not be the strongest of the choices ability wise, it's fun thematically and characterwise. My first 5e character was a blue draconic sorcerer, and I had a blast with him. Even if fire is the best choice, it's still fun to play these sort of characters.