DS>>>GBA&3DS
GBA had far too many ports for my liking particularly SNES ports.
The DS was wonderful balance of games which you would use controls but opened it up for different gaming experiences with the resistive touch screen dual screen...
GameSir G8 Galileo
I've tried it out and was very impressed. It's somewhat reminiscent to a Xbox controller.
Set up a front end like Beacon and you have a gaming device to go.