It’s definitely subjective. Every once in a while there’s an endboss fight where early Hall of Fame Mytbic raid guilds get a large benefit for race changing, but generally speaking racials give you a very minor bonus.
Horde side, I prefer Zandalari and both variants of Orcs. At least until Shaman is opened to all races and this guy becomes a Nightborne.
Alliance side, both variants of Dwarf.
You know da answer, mon.
Also the dumbest looking Shaman.
Enhancement Shaman is the only fun spec in this class