Hhmmmm! I've been liking reading people's thoughts on this!
Orc: Shaman - it's the obvious one, but orc shamans have always come up first when I think of what a shaman is. The connection to raw, powerful elements when combined with orc bloodlust and the connection to wolves just can't be disconnected.
Tauren: Druid, Hunter, Paladin - again, pretty obvious! I know night elves were the original druids, but tauren have that down to earth connection with nature that really hits me. Also, I like their druid forms the most. :,) As for hunters- I especially associate them with spear based combat and muskets- survival or MM with an eagle all the way. As for paladins- I adore the concept of Sunwalkers, even if the game hasn't really done them justice. It's just such a strong mental image.
Troll: Weirdly enough, I don't associate them with any set class so much as a blend. Warlock, rogue, hunter and monk all stand out to me- a blend of them all that becomes something like a Shadow Hunter. Monks are definitely up there, though, with how agile and lanky trolls are!
Forsaken: Totally warlock. It's just too obvious. That said, rogues fit the bill pretty well too, and I've always associated them pretty strongly with death knights! It's probably the whole death part.
Blood elf: Paladin all the way- my first association with blood elves was their introducing paladins to the Horde, and I always adored their aesthetics. Blood knights always intrigued me, and it's an association I can't break.
Goblin: Hunter- not so much the 'friend of beasts' kind of hunter so much as the opportunistic poacher, with an opportunistic pet that reaps the benefits. Think a poacher and their pet hyena! Gritty and oil smudged, making money with just as few morals as the beast world.
Pandaren: Monk and priest, oddly enough- priests not as servants of the Light, but rather the concept of tranquility. I've always connected them with the wardens of emotional balance, so a shadow priest could be channeling the Sha, and a holy/Disc priest would be bringing a healing tranquility to the battlefield.
Human: Hunter and Paladin- pretty basic. The 'male human paladin' trope is too saturated into the world to avoid it, but I always liked the idea of human hunters- your basic run of the mill person with a gun and a dog, out to bring home a deer for the family.
Dwarf: Shaman, Paladin and Hunter- they get lots to account for the different types of dwarf! All dwarves strike me as shamanistic, with bronzebeards and Dark Iron having their strong connection to fire and the earth, and Wildhammer with storms, water and sky. Paladin just- seems right, for some reason. And hunter, of course, because I hardly know anyone who's rolled a dwarf without at some point rolling one as a hunter
including myself, with my hunter main! That said, I pretty strongly associate female dwarves with hunters, especially.
Gnome: Rogue and Mage- I can't exactly see these little dudes being bigtime melee fighters, what with their ability to be gently picked up and blocked from combat by a short hedge, but I've always thought they'd be good at finding ways around that. Strong magic or using poison among them!
Night elf: Demon hunter and druid- okay, the demon hunter one is too obvious and druid isn't much better. I've never connected well with night elves, but they were the very first druids and all- it's so sewn into their culture that the association is impossible to avoid.
Draenei: Priest and Paladin- the Light connection is just too strong for these guys. I especially like it for the potential dark side to both classes, however- with Shadow priests existing, and Paladins having the capability to go way too far for what they feel is 'right'. Draenei are a complicated race with some serious moral issues, and I like that hidden nastiness.
Worgen: Hunter- honestly, another race that I tend to blend stuff together for. Certainly hunter, much for the same reason as humans, but at the same time I can't really see a lot of animals wanting to befriend a wolf-man. Druid, but not the normal type of druid. They're presented as so domestic that it's hard to say!
apparently basically everyone is a hunter but nobody is a warrior. what's a warrior. I've never heard of them