The race has to be playable, you can't just pick Dragon and be done with it.
I'd probably choose one of the Elves simply because they don't die of old age. They are immortal but not invulnerable, so once I've lived for however many thousands of years of life and get bored, I can just kill myself or something and end it.
As for which elf specifically, I'd rule out NELFs because I don't want to be a nature hippy, I'd rule out VELFs because if Alleria constantly hears whispers from the void in her mind, then I'm sure all the other VELFs do as well.
I'd probably go with Nightborne. They are sort of like NELFs except they allign with arcane over nature. Plus they live in the best city in the game, Suramar.