A High Elf is the preferred race for a Magicka Sorcerer, overall it provides a great buff to all your stats. As a Stamina Sorcerer you can pick races such as Dark Elf, Orc or Khajiit. As a Healer it is recommended to pick a Breton, Khajiit or High Elf. And as a tank the best races are Imperial, Argonian and Nords. It is always recommended to check the builds individually as the optimal races can differentiate depending on the build setup.