Though it launched with a whimper, the 3DS has long since roared to life. Even after a soft 2015, Nintendo's DS successor remains great: If you like Nintendo games, there's really no reason not to have a 3DS these days.
On 15 February 2012, Sony of America launched the PlayStation Vita, a powerhouse portable that they promised would deliver "console-quality gaming" to commutes everywhere. Nearly four years later, it's safe to say they failed. But the Vita is a great machine -- even without Sony's help.