This is going to end so well.
The worst one I have owned?
Edit: I misread.
All the home consoles I have owned are great. Does N64 Virtual Console count?
Mario 64 and Zelda OoT do not hold well after playing Zelda TP and Mario Galaxy, almost everything else feels outdated and Mario Kart 64 was abysmal.
I'll go with that one.
I need to clarify that there is no childhood/nostalgia factor involved and I haven't had enough time with Sony/MS consoles.
Edit 2: Man, the X1 hate is strong. I am certain most who voted never really wanted a Microsoft console.