It's not a popular opinion, but I'd go with my Wii. Simply put, my Wii is my all-in-one.
My favorite system is the Gamecube, but my Wii can play all my fave Gamecube games and my fave Wii games. Plus, I have so many retro games installed on the device! Not to mention, the Gamecube and Wii library contain almost all my favorite games.
Edit: I'd go with my Switch as well, because it's new and not easy to get.