Sony PlayStation Portable (2004)
The PlayStation brand had ruled the home console market for over a decade, so it seemed inevitable that Sony would challenge Nintendo's handheld dominance. Early in the battle of PlayStation Portable vs. Nintendo DS, many critics figured that the PSP would win handily because of its impressive graphical, multimedia, and networking capabilities. But that's not the way things have turned out: Instead, the DS has outsold the PSP by a ratio of roughly 2:1. The PSP has managed to do siginificantly better than past Nintendo competitors--mostly because the PSP and DS occupy different niches in the handheld console market.
Sony has introduced three major updates to the PSP since 2004: the slimmed-down PSP-2000 in 2007, the PSP-3000 in 2008, and most recently, the PSP Go.