The Game Boy was released in 1989 and was the brainchild of Gunpei Yokoi, the late genius who created the early Game & Watch. The gameboy's mantra was simple - simple games, with 4 colours (I use that term lightly, they were really 4 shades of grey), and a fairly cool look. This game boy was designed to be not only a game console, but a fashion accessory, something for cool people to put in their bag, 15 years before the first iPods.
However, like any great system, it needed great games, and the Game Boy had them in spades. Firstly Tetris brought a whole generation of people who weren't gamers into gaming, and Super Mario Land was a modified, yet brilliant, game based on everybody's favourite plumber.
With the success of the game boy came other consoles, some even in colour, however a lot of them missed the Game Boy's point, it was simple, designed to be played at short spells, though there were games out there where you could invest time and effort to experience a truly rewarding story. Games such as Zelda: Links Awakening are rightfully called the best games of all time. Other handheld game machines ate up batteries, which the 28 hours on 4AA, the Game Boy didn't. Only at a later date with the color, advance and later the DS did the Game Boy become brightly coloured.
The Game Boy also saved Nintendo from being a bit player in the console world, as in 1996 - 7 years after the console was released, Game Freak released Pokemon to an unsuspecting audience. All of a sudden, turn based RPG's were accessible, and Pokemon became a huge hit, thanks to the Game Boy.