Tetris — The Game and the Lawsuit
The version we grew up on, and the legal thriller behind it.
The NES Tetris (1989) is the version most Americans grew up on, but its real story is a legal thriller. The rights to Alexey Pajitnov's puzzle game were a tangle, and Nintendo and Tengen both released NES Tetris cartridges before the courts sorted it out. Nintendo won; Tengen's version was pulled, making it a collector's prize today.
The game needs no introduction: rotate falling tetrominoes, clear lines, chase the perfect Tetris. The Type-A theme (Korobeiniki) is one of the most recognizable melodies in all of gaming.
Simple, infinite, and the subject of one of the wildest IP battles in game history. I keep the Nintendo cart; the Tengen one is the white whale.