Rating the alliance races:
Human - Male: Muscle bound doofi that are built like a box and have a bad looking run animation. Their box frame makes most armour look meh and they look absolutely terrible is most caster gear (aka dresses). Only redeeming features are their dance, and a couple of jokes.
Bad choice
Human - Female: Good run animation. Their shoulders are a bit narrow and seeing as how Blizzard loves huge pauldrons, this can be a bit of a detriment. Overall though, all amour looks very good on them. They make an excellent looking caster. Dance animation is a bit weak as are most of the jokes.
Excellent choice
Gnome - Male: Silly looking, but that's the big part of their appeal. Most gear looks pretty decent but any detail below the waist is completely obscured by their stubby legs. Make sure you have good looking set shoulders and helm because you won't be able to decern anything else. Great dance -especially when syncronized with a female gnome. Decent jokes.
Very Good choice
Gnome - Female: Pretty much same as Gnome male except for their hyper-cute looking face. Depends on taste.
Good choice
Dwarf - Male: What can I say, they look like dwarves. Run is a bit off, great jokes, mediocre dance. Bigger than Gnomes, so armour detail is much easier to decern. Very stocky, but most items do look pretty good -even caster dresses don't look too bad. Tend to get more clipping errors being the only real downside.
Excellent choice
Dwarf - female: I can't make myself pick one. I just don't like em.
Night Elf - Female: Amazon woman! Gotta say, anything they wear looks good. I'd even go so far as to say that Wrath looks good on them. O_O;; Broader shoulders then female human really helps shows off those pauldrons. Awesome dance, poor jokes, and a run that's almost perfect save for the mechanical horizontal arm fling.
Excellent choice
Night Elf - Male: HUGE shoulders and a tiny waist make anything -much like their female counterparts- look good on them. Bad run. Bad faces. Bad hair. Bad jokes. Bad dance -though oddly it suits them. I can't stand Night Elf males. They REALLY bug me, but gear does look good on them.
Bad choice
My top alliance picks: Human Female, Night Elf Female, Dwarf Male
Wish I had more experience with the horde, but here goes:
Undead: Really cool race overall, hunch doesn't even bother that much since it seems fitting, but I HATE the tattered armour thing. Yes, it's neat early on, but gets annoying quick.
Hunch level - tollerable
Tauren: Probably my favourite horde choice. Male only. Some gear looks awful on them though. Must be quite hard to adapt armour to "fit" them.
Hunch level - tollerable
Troll: I like the troll males. Troll females are a sad attempt to give the horde a "hottie" choice. I SO wish male trolls would stand up more.
Hunch level - annoying
Orc: Never played one.
Hunch level - annoying