The grand-daddy of all puzzle games, Tetris has appeared in some form on just about every gaming console ever. Okay, maybe not for the Pippin, but you get the picture. Want to get your hands on Tetris today? Take your pick of Tetris on the Wii, Nintendo DS, PlayStation Portable, iPhone, iPod, or Xbox 360, just for starters. But it was the release of Tetris on the original Game Boy over 20 years ago that made it a worldwide phenomenon, and it’s now dropping its puzzling perfection into the number two spot on our list.