Their casting animations annoy me. Their attack animations annoy me. Their ready stance annoys me.
They are often hunters or rogues, both of which I hate. They are also druids, especially resto, which I hate even more. And to top it off, they are even warriors.
They are ugly. Their skin is strange colors. They have fangs for no good reason. Their men always have ugly expressions.
Their quests irritate me. They are often emo, often boring, and often have bad rewards. I can understand the Forsaken having emo quests. Let's see you be cheerful after dying and then coming back as an absolute slave in all aspects except your ability to be horrified at what you are forced to do.
They are arrogant and constantly telling other races what to do. They have no honor, nor do they even have capitalistic greed. Instead they are motivated by their arrogance, pretending they are the ones that will save the world. A thread that pops up now and then shows how it was nelfs that pretty much ruined everything. It was nelfs that made guilds have to do that god-awful quest to rebuild the AQ scepter because a nelf broke it. They brought the Burning Legion here. Illidan is a nelf. It was other nelfs that released him. And it was more nelfs that interrupted him when he was destroying the Lich King.
Humans? A little boring, but cool. I don't like dwarves too much, but I have to admit they are pretty cool. Gnomes are annoying, but definitely cool, though they did nuke their own city. Draenei need a bit more understanding of races that haven't been indoctrinated by Naaru for thousands of years, but they're generally decent. Of course the Horde is awesome, especially trolls, orcs, and tauren. Forsaken are pretty cool if you take into account the trauma they've been through. Belfs are a bit too much like nelfs, but at least they had the decency to not turn into snakes.