While Michael Jackson's Moonwalker may be the height of gaming absurdity (the premise is actually Michael Jackson rescuing children it probably would have been wise to avoid the topic of children altogether in a Michael Jackson game, right? Plus, the Thriller level didn't even play Thriller) his appearance in Ready 2 Rumble Boxing: Round 2 was far weirder. It's not only that he let them use him as a character he went in and did the motion capture work himself. He was dedicated to appearing in this sorta-okay fighting game, where the frail, pacifist singer (listed at 125 lbs.) faced off against huge behemoth fighters. The game didn't even include any of his music the one thing you might think a Michael Jackson appearance would bring to a game. At least the developers can rest easy knowing someone had the bright idea to make one of his boxing gloves all sparkly.
If you can defeat M. Bison with Zangief without being touched, two things will happen: you will likely be burned at the stake, because you must be a witch or something to have done that, and also Mikhail Gorbachev will fly in on a helicopter to congratulate you, very slowly tell you how proud he is of you, and then do a stereotypical Russian dance. Hopefully afterwards, he took Zangief to a barber to get his shin hair trimmed a bit. It should also be noted that the original arcade Street Fighter II came out mere months before Gorbachev was forced out and the Soviet Union collapsed. Every additional iteration of the game (including the Super Nintendo port) took place after his resignation, making his cameo even weirder. I wouldn't put odds of him appearing in Wreck-It Ralph too high.
There was a brief period in the 90's where Shaq said yes to pretty much any offer he was presented with. A rapping genie who lives in a boombox? "Sure." A weird, Iron Man-esque movie starring Judd Nelson? "Yeah, okay." A cheap Mortal Kombat knockoff? "Well
add an evil mummy to that and I'm there." Shaq Fu, living up to its really, really ridiculous name, was about Shaq having to use kung-fu in an another dimension to rescue a kid from an evil mummy (uh, cliche much? Interdimensional mummy kidnappers were so done by 1994). Why anyone thought Shaq would be a good fit for a fantasy fighting game is a question for the ages. Then again, if it allowed them to come up with lines like "Your wrap is whack, brah!", who are we to question such genius?
For some reason, US Presidents often get featured in videogames, and rarely doing anything remotely presidential. This is the closest thing to political discourse in gaming. The list includes: