The PVP “Enthusiast”
You know this guy—he's the bloodthirsty one. He's always looking for other players to kill/maim/harass, consequences be damned. If you party with him, he'll ignore whatever objective you're working on the moment he catches sight of a player from an enemy faction... even if the enemy player vastly out-levels him. If he dies (and die he will), you'll be to blame. “Dude, why didn't you help me fight that guy? Jeez, you're such a noob.” While the PVP Enthusiast is fun to hang out with, he'll always be getting you into trouble—and helping you make enemies on the server.
The Helpful Guy
The helpful guy is one of the more pleasant types of people you'll ever run across in an MMORPG. He's probably reached the level cap and has some of the best gear in the game, but doesn't really like PVP too much, so he spends his time helping newbies. He'll give you gold and equipment and help you level up—unfortunately, so many people take him for granted, he's constantly under fire from other “friends” for his assistance. Do the right thing and once you get more powerful in whatever game you're playing, return the favor. Offer to help him level up a new character, or help out some of his friends.
The Girl (Not Really)
The ancient and sacred rule that states There Are No Girls On The Internet holds especially true in MMORPGs. That cute level twenty elf girl over there is really a fat dude sucking on a can of red bull. He'll try to pretend to be a girl for a number of reasons, usually a sick fantasy or, more likely, free items—have you ever given gold or items to a “girl” in an MMORPG? You got scammed, sucka. The worst part about these guys is that they tend to act as extreme, saccharine caricatures of girls. Expect lots of ^_^ faces. For example, “Tehee! Can I have that incredibly rare +4 Sword of Crossdressing? I can? Gee, thanks ^____^.” The real girls who play games aren't (usually) this annoying.