Most of my favs from each gen are the "losers". Gamecube, Xbox 360, PS3, Xbox One.
Can't really decide personally. All the ones I named were noteworthy for something and deserved better sales.
I think if the 360 had not had red ring issues it would've beaten out the PS3 in overall sales, but that's not to discredit the comeback the PS3 had.
And as unpopular of an opinion as it is on this site, I still really like the Xbox One.