Ketsui Demo Label: Ketsui Death Label, a Boss Rush DS port of the arcade game Ketsui. Its inclusion of only one full stage has led fans of Shoot Em Ups to call it an expensive demo version of the arcade original.
Metroidvania - Very common nickname for 2D action-adventure game featuring a single large environment you slowly get more and more access to. More specifically used in the Castlevania fandom to draw a distinction between the 'old-school' style of games and the newer ones, circa Castlevania: Symphony of the Night.
Classicvania - Counterpart to Metroidvania above, when referring to most pre-Symphony Castlevanias, which were linear action/platformers.
Madden (insert year) has often had the derogatory nickname of "Roster Update" due to the fact that other than the rosters being updated per season, it's been a long time since the games have introduced anything truly new.
Portal Kombat - Mortal Kombat 9, due to its release date coinciding with that of Portal 2. No one could resist the urge to swap letters. (Said nickname is a mutual one shared between the two games.)
Mortal Kombat 9 is itself a fan nickname, since the game is actually just called Mortal Kombat. This depends on who you're talking to - other communities prefer to call it Mortal Kombat 2011.
Video game peripherals:
Wiimote: The Wii Remote.
Note that this is actually the official name of the controller in French, as it is written on the box and handbooks. The litteral translation "Télécommande wii" is the alternate name: understood but hardly used by anybody.
In French-speaking Canada, L'Académie française (or French Academy) exists specifically to maintain the purity of the French language; only words and phrases approved by that department are considered 'real' French. 'Télécommande wii' would make the list of 'official' French, while Wiimote, despite its being the 'official' Nintendo-approved name, would likely not make the cut.
"The Nunchuk" was an unofficial name for the prototype control stick attachment, but became official because Shigeru Miyamoto liked it so much.
The Duke: The original Xbox controller, before the smaller Type S was adopted as the standard. So named because it was big, broad, and took big manly hands to use comfortably.
The Bone Controller: The standard controller packaged with the model 2 NES (a.k.a. the Top-Loader) shaped like a Super NES controller, looking almost like a bone.
Oh, you run a server in Garry's Mod? You also happen to abuse such power? You're an Adminge.
Micspammers - people who play a song over the microphone over Team Fortress 2. Usually it is a BONK song.
Ninjaneers - Engineers who seem to get more kills with their wrench than with their sentry.
Or Engineers that manage to set up a sentry behind the enemies.
Leeroys, Leeroying, Leeroy Jenkins - A player who, in an MMORPG, either ignores orders or causes a bunch of unnecessary aggro. Leeroying also refers to an action taken, such as aggroing a group of enemies.
MINUS 50 DKP!!!, 50 DKP MINUS!!!, Pakistani Raid Leader - A type of "Stop Having Fun" Guys type of person who loses it when people start messing up or does something stupid. It was named for a raid leader who, in the game World of Warcraft had said that if people messed up during a raid they would lose 50 DKP. Then when something goes wrong he proceeds to yell and freak out, yelling "THAT IS A *** ING 50 DKP MINUS!!!" at the player. It was thought that he was a Pakistani player on the Europe Servers, since he had a clear accent.
The raid leader in question is Dives, a Romanian-born WOWer who founded and leads a guild known as "Wipe Club," and who used to be in the military. His ranting style is very reminiscent of a Drill Sergeant Nasty, and his other major rants can be heard here.
Team Ninja Dog - Derisive name for Tecmo's Team Ninja studio without Tomonobu Itagaki's involvement. Coined by fans of the modern Ninja Gaiden games mocking those not made or approved by Itagaki (NGIII and the Sigma re-releases in particular).
Video game consoles:
The Purple Lunchbox: The Gamecube, so named because of its indigo color and weird "handle" at the back.
The Toilet: Atari Jaguar, which really resembles one when the never-used CD add-on is attached. Also named because of the questionable quality of its games.
George Foreman Grill: PlayStation 3, due to its bulky design and tendency to run really hot while you're playing it.
RTS Genre: Some strategies which are possible in many of the genre is "Booming" (Emphasizing economy, will probably beat turtling), "Turtling" (Emphasizing a defensive strategy, will probably beat rushing) and "Rushing" (Emphasizing quickly creating a military force to attack as soon as possible, will probably beat booming.)
Fuckoff Strong: Title given to any foe that trounces you so badly that your reaction is "Oh fuck OFF!"
Spacebucks: The virtual currency used to purchase downloadable games for any of the three seventh-generation consoles: actual money for the PS3, Nintendo Points (previously Wii points) for their systems (except for the Nintendo 3DS and WiiU, whose eShops use real money), and Microsoft Points for the Xbox 360. Can also refer to any virtual currency on any website (or online game) that is bought with real money.