THE WIZ
No matter the game, this person wants to play a wizard of some type. If it's
Call of Cthulu, he's the first one to break open the occult tome and start reciting incantations. In a non-magic game, they still try to make magic work somehow, no matter how hard you try to explain that it
won't work.
THE DABBLER
Okay, I'll admit to doing this a few times myself.
Basically, they always create a character that's the opposite of the SPECIALIST. This character has at least a couple points in
every skill, meaning they're not actually good at any of them. Usually gets upset when their low skills keep failing checks.
THE NON-COMBATANT
Gah. We all know that, at some point in an RPG, there's going to be a fight. However, this particular gamer refuses to ever put their character in danger. Slightest hint of a confrontation and "My character finds the nearest exit." If there's a possibility an adventure might require combat, their character decides to stay home and read a book.
THE MYSTERY MAN
Similar to the LONE WOLF, this character refuses to let the other characters know anything about himself. Either he's constantly under illusions, never at the meetings, or uses some sort of proxy whenever possible (crystal ball, drone robot, etc.). Only when the adventure begins does he show up, and he takes great pains to drop annoying hints about his secret allies, the resources at his disposal, etc., until he can vanish into the shadows again. Mysteriously.
THE 'WRONG GAME' GAMER
You've seen these, most likely. The person comes to a D&D game and says, "I want to play a vampire." Or, comes to a LARP and says, "I want to play a mind flayer." Basically, this person just wants to stick to what they know, or exploit the power-level of their old game in the new one. There's no effort on thier part to integrate into a new game, they just want to take their previous characters and slap them in place.