DSi introduced region locking to Nintendo handhelds. I stopped buying them at that point. The next Nintendo system I bought was the switch, which was no longer region locked. The DSi kicked that off, so it might be my least favorite.
Favorite hardware is a much tougher nut to crack. Could be my first console, n64, or my first gaming apparatus, the Gameboy Pocket. But the PSVR1 blew me away and made me a little less into flat games. The PS5 has everything I love from PS4 onward (and does VR), and the Steam deck streams my PS5 from bed while also playing pc, retro, and Xbox games and being a full on Linux machine.