I've gotta lot of thoughts about them, so i'll probably visit this thread back and forth over time. Everything is cyclical @Luseth so they won't really ever die out imo. People want everything in one space like your phone, but with games because people will demand more in the coming years of AAA games, mobiles won't be able to handle them as they'll be a Jack of all trades, Master of sweet FA. Look at the camera industry. Don't need them as much now because of phones, but there is slowly becoming a resurgence in fully fledged standalone cameras because they give you more freedom for the people that love taking photos.
Gameboy is where I started so will always be close to my heart, sorry @phil bottle. It was a great device that got me into games, although they don't hold my attention too long because I love home consoles way more. I'd Game Gear was up there for me. My cousin had one, loved the colours in Columns and the size of it was awesome. Big but not ridiculously huge that it couldn't be taken anywhere. I wish the PSP held me more like you @Luseth, it really was a great device. The PS Vita should be held in higher regard but I think the games on the PSP were more true gamer style and it was an added boost we could watch films on it too!
Out of everything, I'd say the Switch is unreal. If it had a better online way of connecting and keeping in touch with everyone, I think i'd be on it so much more. I'm with @Spacedeck when he says its seamless from hands to TV. And lets face it, if the games are awesome then thats where most of us end up. The games on the Switch have that unique flair that i'd say was similar vibes to when the Gamecube came out and was literally better than anything i'd played before. I do wonder if Nintendo gets that multiplayer online space right in the future, they could change the gaming scene more than we realise.
I'll come back and talk Neo Geo Pocket soon...