Joe Walmart - n. - "The lowest common denominator consumer that many publishers must cater to in order to mitigate financial risk. Coined to describe the powerful force that allowed Deer Hunter to become a market success. Can also be referred to as 'Walmartian.'"
If there is a phenomenon in gaming that drives you crazy, someone has probably coined a term for it. Gamasutra compiled a list of semi-common slang terms from industry professionals, a list that reveals a lot about why games are the way they are.
For instance, if you've ever done something trivial and received an absurd in-game payoff, you've "pushed buttons to make rainbows". It "refers to a neighborhood of game mechanics and/or interactions where the psychological reward given to the player is disproportionately larger than the effort required on the player's part."
Or perhaps you'd like insight into the glamorous world of game development? Then prepare to meet the LSD - "Light Sensitive Douche. A phase some developers go through where they get a bit of fame and feel that wearing sunglasses indoors is the right image for them." Beware his friend, the sponger: "Anyone who goes into a bathroom with their shoes off."