For me it would be switch. I've always wanted a truly portable console. It's been a dream of mine for 25+ years. Seamlessly move between couch and portable play. The boundaries are gone. If I had seen it 20 years ago my jaw would still be working its way off the floor.
Turboexpress portable was 1989. Transfer game cards from the home console to portable to play on the go.
Psp 2000 was 2007. Supported AV out to television to play games on screen or on tv.