I got this from a post on usenet. I thought it useful. It did make me wonder if this DM had problems of his own, though.

We've all played with some good and bad gamers. Which FIVE of the following fifteen player-types do you hate to game with the most?

Munchkin. Loves to brag that his character will 'win the game.' Wants to have the perfect combination of magic items and high levels so that he can feel, in his own mind, that everyone else thinks he's the greatest character on the planet. After he get's the perfect combination, he rubs it in the DM's face, securing his future. He hopes that by irritating the DM, he can be faced with 'the ultimate challenge'..which he knows he'll win ironically easily. Would play the psionist even more often, but he belives that there aren't enough good magic items out there for him to gain.

Min-maxer/Efficiency-fanatic-wargamer. Get's pissed off at other players if they make an elf and don't take a long sword and bow for the weapon bonus. Loves the players option books, because he gets to min/max everything. Tend to like to tell other players what to do, so that the session runs more like a military operation, than a game. Demands that the DM use spell points, character points, and merit points. Never uses PC names. Usually says things like, "Thief, go check the door for traps. Mage, cast a fireball on 'that' battlemat square." Knows more about your character than you do, and assesses blame when something bad happens to their character.

Notta' Role-Player. Cannot role-play to save his life so he makes character backgrounds as, "Mysterious and quiet." He is so introverted that he rarely says a word unless asked. Conjures a great game in his mind, but never shares it with anyone, unless he blurts out some inane pseudo-role-playing statement like, "my elven-fighter says, "grrr. I'm going to get you..you..orc." His idol is Silent Bob. Will oftentimes stare at everyone else, chuckling to himself, as if he has some dreadful secret.

Vocal Rules Lawyer. Will argue with other players or the DM if they feel that the rules might be violated in a way that will affect him or his mission. It's OK for him to bend the rules, but other players cannot. They also tend to make up arbitrary 'false rules claims' if things aren't going their way, just to make the DM make a hasity ruling on the spot. If the rule has significant loopholes, he'll settle his case momentarily and conveniently bring it up again later with the saying,"but last time you ruled..[insert twisted and false claim ruling here]." Enjoys arguing for the sake of arguing, while forsaking the game and the other players' time.

DM Antagonist. Always bored, because "I've been there, done that." So you like to try to throw the DM by going in deliberately antagonistic plot directions that gives the DM a big headache. Always asks the DM to look stuff up for him, usually during the peak situation of the game, because "he can't find it in his book." Likes to cross over player knowledge with character knowledge by claiming that his half-orc has created gunpowder, blinding powder, hand grenades, gattling-spearguns, and complex feats of engineering. Pouts when the DM disallows these things.

Lone wolf. Character player, who will often tend to sneak away from the group to 'see if they can find a little extra loot.' Other players and the DM are always pissed off because he is wasting their limited gaming time (although he doesn't realize it, because it's his god-given right to play his thief that way.) Wants incredible details of his move-silently actions or what he finds in the merchant's pockets. Is still pissed off that experience is no longer gained by defeating/sneaking by monsters and gaining treasure.

Immature and petty whiner. Tends to do stupid or childish things when the game isn't going their way. Will carry over petty grudges with players or characters in different campaigns. Will often do dumb things like start a wrestling match with another player, or will unhesitantly punch the Lord-Mayor of Greyhawk in the face if they get even the slightest bit annoyed. If their character dies, they will storm out of the room or sit and cry to the DM or other players about how UNFAIR it was.

Mutinous and opportunistic prankster with malice and aforethought. Likes to create problems for players just to see other players fight or attempt to get out of tough situations. Will, 'accidentally' fireball the theif if he gets in the way. If no one else is paying attention, his mage-thief steals the campaign-crucial, holy-avenger sword from the tomb and sells it to an NPC. If he didn't start that way, he'll work towards getting an evil alignment. Tends to like to create characters that can do it all, but will withhold all actions, just to see the party squirm, then charge in to save the day.

Overbearing, extroverted, actor-wannabe. Personality that talks too much, and usually in a really irritating accent. He never lets anyone else speak. They think they have a lot of great ideas and everyone needs to hear them. Can breathe through his ears, which helps him chatter his jargon without abandon. This person always wants to sit right next to the DM or in a position that puts him where he can obstruct action without much difficulty.

Lost and Confused Space Case. This person always forgets their character and doesn't have any organizational skills at all. They don't have a clue about the campaign, and are often more interested in their computer games, or something else not related to the game at hand. Other players take advantage of him and trade him beads for his magic items. Doesn't own a players handbook or dice. Lives with his mom. Appears to be on some sort of illicit drug, but no evidence can be unearthed. Say's "Dude" way too often. Likes to play a spellcaster and has to look up the definition of magic missile and cure light wounds at least twice per game.

Quitter. Tends to drop out of a lot of campaigns because they, "Can't find the time." Really interested for the first 1-2 sessions and get's the DM and other characters to spend an inordinate amount of time preparing a complex character background for him, possibly with the campaign revolving around something special about that character, but then quits the game. Has probably tried to make his own game because he doesn't like the AD&D rules. A subcategory of this type of player is the Unreliable. This person shows up 1-2 hours late without warning, or not at all during crucial gaming sessions, but still has most of the traits listed above

Beuller..anyone..Beuller..Story Teller. Likes to talk about inane statistical character or game details for extended periods of valuable gaming time. Often times considers self to be an expert at explaining military and medieval details, especially in the long-sword versus broad-sword debate. Also, tends to tell a lot of boring old character stories, regardless of their relevance to the current game. People just nod their heads when you speak to them, unless you are speaking with another of your kind, at which time the room clears out. Knows all of the band-aid-justifications of the out-of-date-Tolkien-based-AD&D-racial-systems, such as why elves raised in a city, by human farmers are experts at longswords, bows, and invisible movement in woods. Kicked out of his philosopy class for casting sleep spells.

Automaton. This person is controlled by their wife or another member of the group. Cannot think for themself. If the wife or girlfriend is present at the game, he is always in trouble. Spends a lot of time kissing ass to the significant other. Probably likes to play, but always ends up dropping out because of the inability to control ones own life. A gimp. Has to ask others what to do.

Cheater. This player has never had a die roll less than 14 on a d20. They usually sit as far away from the DM as possible. Puts all of his stuff on the table, so as to mask as many rolls as possible. Uses a lot of practice dice rolls or 'plops' them from less than 2" off the table. Spins or stacks dice. This person wants to make a character during the middle of the game session, during a combat, because he knows the nobody can observe his rolls. If he is a spellcaster, he will claim that he cant find the rule. Carries large stacks of paper, so that the DM cannot possibly see his entire spell list. Never writes anything down. If the DM asks for his spell list, he claims that he left that sheet at home.

Uptight Grump. This player is always cranky or tired. People fear him because 'he don't like nobody touching his stuff.' Has wrinkles from frowning and chalk marks from dried sweat. Swears, breaks pencils, and throws dice when things don't go his way. Makes his own diamond dice 'internally,' using coal. Most of his character sheets are crumpled up, and books are in serious need of repair. Sits near the pencil sharpener (which scares people more). Drinks Surge, Mountain Dew, and Double Espresso and eats food that complicates the situation. Smells bad. Usually plays a horribly complex character.