Gameboy
"In the mid- to late-1980s Nintendo captured almost 80 percent of the U.S. market for home video games. Surveys found that Nintendo’s Mario character was more popular in the United States than Mickey Mouse. Nintendo’s Game Boy, a hand-held video game system introduced in 1989, became extremely popular in the United States due to the success of Tetris, a game involving interlocking blocks. Later Gameboy Color and Pocket were introduced. With their success, Nintendo created the Gameboy Advance, a Gameboy with higher quality graphics and more functionality. Next was the GBA SP with an internal light and folded over into a square so it could fit into your pocket."

-From Encarta Encyclopedia and Wikipedia