I actually have a bit of my own vocabulary that me, my cousin, and a couple of my brothers use often, along with this friend of ours:
Crusty Mustard - This term is used for games that have really rough controls. I first thought of this term when playing O.D.D. for Playstation at my cousins house, and those words just came out of my mouth... it really was a magical moment, I believe god put those words in my mouth to describe such gameplay. Another control term we use is "soapy", and this is kind of the opposite of crusty mustard because when you say soapy, it means the controls are too slick, like when you are in a ice stage for some game and your character slides around a lot.
Metallic Nutz - You typically always use this in the phrase "<whatever here> sucks metallic nutz." So if I may make an example myself, "Energy for PCE sucks metallic nutz". Sometimes you can use this as the opposite, like "Keith Courage rocks metallic nutz". Not quite sure how I came up with this one again, but damn do we use this a lot.
Butter Zone - This is some vocab me and the gang got from the movie Hackers. There is a scene when Dade and Lord Nykon are checking out Acid Burn's "fly laptop" while she is making out with a guy in the dark. She hears them and is surprised and asks them what the hell they are doing, and Lord Nykon says "You're in the butter zone now, baby" and gives a nod. It was funny because we didn't notice this line until the thousandth time after we watched this movie and we have been using this line ever since!
3vilw33t - This one goes back to when me and my cousin were once playing Skitchen on his Genesis, back in 2001 when I wasn't aware of the 3vil l33t talk. Anyways he's typing in his skater's name and types in "3vil l33t", but I swore back then that it said "3vil
w33t"! So ever since then I've been saying 3vilw33t instead of 3vil133t and everyone always gets confused. I use this word to describe something that rules.
BEEF - I know this is one that people somewhat casually use, usually in the terms of "I have beef with you". However we usually use this one for when you screw up in something. Like if you were playing Out Run or something and totally crashed into a car, I would say "Man, you totally beefed it!".
Duck Hunt - Oh man, this one is the king. You see, me and the gang have this quad-annual video game tournaments, and in the first one, we had Duck Hunt. My cousin isn't very good at these old light gun games, and we first found that out in the tournament when we played Duck Hunt. Me and my bro were ranking a huge score in the game, and so when it was our cousin's turn, he only shot like one duck in the first stage and failed miserably! We immediately started using this term for when someone REALLY screws up in a game, and when I say immediately I meant it, because when it was Julian's turn next, he was getting really close to beating my bro's high score, but I told him a joke and he was laughing so hard that the Zapper was shooting in all different directions and he failed the stage terribly! So from that moment on we started using Duck Hunt a lot

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There are more phrases we use, but I can't think of them at the moment. We're just a bunch of strange nerds.