The PSP .
I know is not "failed" as others in thread but it had pretty lackluster software sales in west due CFW/Piracy i suppose.
It had so many games, like games after games. Even people dissed Sony at first and thought DS was gonna kill this in a month it was no joke.
I played some of best games in gen with this little machine. Itself was so good too, build quality,battery life, Web BROWSER,MEDIA CONTENT (NINTENDOOO), Wifi gaming.
Tekken , GTA, God of War,Marvel Ultimate Alliance, Street Fighter Alpha 3, Luxar,MGS, Mortal Kombat Unchained(goro baby),It even had remote play , i played alan wake on it.