As anyone who plays WoW knows, the world of Azeroth is full of characters! Of course, said characters have all sorts of various personal temperaments, but here is a brief list of the player types I seem to encounter.
This player is the one you want in your group when in instances. They are the silent, but deadly type. Not to be confused with the GO GO GO Dude (see next type), they may not be much for small talk, but do lend instance tips and strategies to those uninitiated. Often, they wait to make sure everybody in the group is on the same page. Not specific to any particular role. If you get a Mr/Ms. Efficient in your group, get ready for a smooth run.
GO GO GO Dude
This is self-explanatory. This is the player who (usually a tank from what I've witnessed), as soon as everyone gets into the instance, starts running off and pulls mobs, not allowing anyone a chance to buff. He, or she, usually has a high gear score number, and doesn't take into account that not everyone in the party has a 5700 gs. They say things like "let's clear this in 5 min.", and always goes straight for the main instance boss. Wrath be to the party member who wants to defeat all the bosses for triumph emblems. They are efficient of course, but probably too much so.
This player is one you actually want to bother with (for me at least). They are experienced instance runners and raiders, yet haven't forgotten that WoW is ultimately about making connections with other players. They don't mind lending a hand when someone asks, and are able to lighten things up, even making (or trying to) small talk in instances. While they may be experienced players, they are patient with other players, and don't call out players mistakes. In an ideal world, instance and raid teams would be made up almost entirely of these players. They also act as an ear if you feel like your in a rut with your toon, and are willing to give advice.
Ah...that jerk. Another type that doesn't need explanation. Probably a person who has self-esteem issues in real life, and takes it out on other pixels. These players call out the mistakes of others with such phrases as "u suck noob", "lol huntard", among other encouraging words and phrases. This player can literally ruin the WoW experience for players who let these jerks get into their heads (they've affected me, and I'm not the only one). There's bound to be one in your party, and they either leave after bashing someone, or cause the party to fail.
This is just s short list of player types that seem to populate Azeroth. Of course, there are plenty of others, but the ones on the list seem to appear the most.