Nintendo's first generation of handheld and by many mean the most success because no one was expecting it launched with one game that helped it and that is Tetris, along with that there were many other portable versions of other big Nintendo games such as Mario, Metroid and Zelda. There was a period when even the Gamboy had a slump but had a massive revival thanks the one game series and that is Pokemon a series that has went on to be a system seller on it's own. The Game also went through many hardware changes in its life with the Gameboy pocket being the first and then the Gameboy Color being the most radical adding colour to the games for the first time essentially making it a handheld NES in terms of power and going on to sell more than the original model, all made possible thanks to the Pokemon revival.
Nintendo Gameboy Advance
After the success of the original system after its revival Nintendo launch a new system on par with the SNES in terms of power and in terms of game quality too far out doing the Gameboy Color in terms of sales with a mix of SNES ports and original games the Gameboy Advance had one of the widest varieties of games that could suck you in for days on end, on top of that it was fully backwards compatible with original Gameboy titles. Much like the original the Advance also went through several hardware revisions later on removing backwards computability when the Micro version was released.
With the success of the GBA Nintendo was set to release what they called the third pillar of their console range whether or not that was to play it safe or not no on truly knows but with the release of the DS they completely out done and outsold even the GBA pretty much making their minds up there were only going to be two systems. What made the DS so different to the rest was its two screens and touch screen adding a new level of play for games and also offering the power close to that of the N64, much like previous systems it went on to break all of their records in terms of units sold thanks in no small part to the quality and quantity of the games. Again like previous systems there would be hardware revisions each one adding something new and later again removing backwards compatibility with GBA games.
Nintendo's latest system following on from the DS adding a top screen that delivers a 3D image without the need for glasses as well as analog control, the ability to take 3D pictures and movies and a gyroscope. Mixed with the best online a Nintendo system has possibly had and power that matches that of the Gamecube and Wii, things are looking positive already for the system.