Aimbotters: Especially annoying when using NPCs, as NPCs don't get to argue about munch...
A: Three hundred seventy of my trained assassin gymnasts crest the hill, sight you, and rush toward you.
B: Luckily, I have three hundred sixty-nine bullets in my chain gun! I quickly mow them all down, each taking a single bullet to the head, and peg the last one with a rock in the sternum.
Godmoders: Obvious.
A: Now that you're strapped to the end of a naval cannon, I fire it.
B: Whoosh! I nimbly dodge, somehow forgetting the fact that I'm restrained by three-hundred-pound chain!
IDKFA-ers: Most likely people attempting to emulate Solid Snake or some other cheesy spy-novel hero.
A: You're all out of ammo for all five of your Ingram submachine guns, 501!|). Since you're buck-naked, I know I can now safely step into the open and begin returning fire.
B: Ha! Little did you know, I have twelve shuriken hidden within my pubic hair!
Twinks: Sometimes allowed in certain RPs. If the RP isn't specifically about invincible deities and such, a simple rule is that if the strengths aren't counterbalanced with relatively equivalent weaknesses (or if the reasoning behind the phenomenal cosmic powers isn't eloquently and appropriately explained), you're dealing with a twink.
A: A punch coming, eh? Well, seeing as you're a seven-year-old child and I'm riding in a twenty-meter mecha, I won't bother dodging.
B: Fooled you! I have the power to DESTROY EVERYTHING when I punch it! I'm just like an X-Man, and therefore require you to suspend all logic when RPing with me! Oh, and I have the power to steal your girlfriend, too.
Min-maxers: Not a lot of those running around here, thank goodness... that's more of a DnD-style paper game issue.
A: I've successfully broken into the facility which gave you your incredibly 1337 power armor. Now I pull up the file on it. What does it say about weak points?
B: The metal of my armor is... um... allergic to praying mantis urine.
Miss Cleos: Obvious.
A: ((OOC: There's a secret switch hidden in the lamp.))
B: I suddenly think to myself-- why not check the lamp for hidden switches? Call me now for your free reading!
McFlys: An all-too-common menace.
A: Ha! Now that the force field is down, I run inside your evil lair!
B: Um... um... there's also a super-secret second force field which causes you to die instantly! I just didn't say anything about it because... um... I had to do my laundry! Not because I just thought of it now! Honestly!
Puppetmasters: Another overly common occurrence.
A: I step carefully into the room, peering around for occupants.
B: Suddenly a dragon pokes you in the eye. You run screaming from the room, whereafter you go home, make a pickle sandwich, and call your mother to cry about how she ruined your life.
Daydreamers: Not exactly munch, per se, but it does get annoying.
A: In the middle of the intense shootout, I dash across the narrow alley, ducking and weaving in hopes to avoid getting hit. I'm unsuccessful; two bullets peg me in the shoulder, throwing me back into a Dumpster.
B: The bullets make me think back to my days as a youth, when I had to melt down tin soldiers to use as musket balls against the Redcoats... or was it redskins? I can't remember. Anyway, I had to walk uphill all three ways to school and back, running from glaciers all the while. It was torture, lemme tell ya. And then there's the story of how I met my first wife...
Shoe elves: Pretty obvious.
A: ((OOC: Well, gotta go to bed. Big neurosurgery test tomorrow.))
B: Ho, ho, ho! Now that the loser's gone to bed, I can strap his character to a cross and peg him with rotten fruit!
Revisionists: Another prevalent problem.
A: You chose the blue pill? Ooh, tough luck.
B: Red! I said red!
Don't go pulling that "I can read your previous post" mind game crap, either!
Speedhackers: One of the worst we have to deal with.
A: I walk to the door and step outside.
B: Suddenly, twelve men grab you, carry you off to my secret lair in Tibet, and torture you for weeks. When you finally die from the agony, we bury you in the frozen wastes. Hundreds of years later, arhcaeologists discover your frozen body and try to determine if you're another Lucy.
Oxymorons: Luckily rare.
A: I'm a farmer with a shotgun.
B: I'm a black hole which emits blinding pulses of visible light!
Baghdad Bobbits: An advanced (or is that "degraded"?) form of Puppetmaster and Aimbotter combined.
A: I fire at the stationary target, hitting twice but missing with my remaining four rounds.
B: I get tired of your realistic RPing style and poke you in the neck, collapsing your trachea. You die writhing in torment.
Gaseous Snakes: An advanced (or is that "dumb"?) form of McFlys.
A: I walk to the door and open it.
B: Being a fellow with a bit of foresight, I hooked that doorknob to a car battery an hour ago. You're thrown across the room.
Augustines: Far, far too prevalent.
A: Given that this RP's technology base is midieval, I happily drive my cart to the market to buy some maggot-ridden meat.
B: Too late! I already got there in my Gundam and blew up everything with my insanely overpowered weapons! And don't start whining, because my Gundam's already pre-approved in the "This Is Not a Midieval Technology Base RP" thread.
Batmen: Only a few, but they're a b***h to deal with.
A: In this Fantastic Four RP, I'll be Ben, the gruff rock-man with a heart of gold.
B: I'll be Reed Richards, the living sex toy who hunts down innocent women to subdue with his incredible flexibility!
The people who alter thier character as needed for the situation (Zoicite).
Example: They can turn from an angel to a demon to a dragon to a gundam pilot to a janitor to a literal fly-on-the-wall to an ogre magi to the sacred holder of that important plot element that they need to do what they want.
The people who declare their IC threads safe, but readily attack others (NIMBYs).
Example: Any attempt to do anything hostile is deleted (Or they just declare it invalid, in the case of Barton Town or Commerce), and some with more balls than others may even file a complaint over the intrusion with the admins. After they have their home, they launch attacks on other threads and retreat to the 'safety' of thier home. This is shown by "Oyakata of Midori" and his "Gaian Mafia HQ" thread.
The people who gain abilities as they need them with no prior exposure (Trinities).
Example: Trinities are the kind of people that can get into any kind of vehicle et-al and pilot it like a pro, or use any weapon with exceptional aim. They an come from a mideval farm and shoot a gun, drive a car, pilot a mech, fly a spaceship, use a computer, etc.
The people who pick-up things that spawn from seemingly nowhere (Quakers).
Example: For example, Ushida going from having a single gundam, to having a gundam and a spaceship, to having a gundam and a spaceship and a fleet of spaceships. Likewise, Scott2003 went from having nothing, to having a metal gear, to an island nation with hundreds of metal gears and 115,000 Matrix-squids and thousands of civilians and vauge equipment that makes things matrix-like and a fieldthat disables all electronic devices and etc...