I had a lot of fun with emulation on the Wii and generally considered the Wii controller options a strength of this setup.
The Wii Classic controller is an excellent and robust wireless option that works with pretty much all emulators and it isn't hard to find or pay for one.
Best of all is using the Wiimote motion controls for 2600 paddle games, a truly excellent way to play these games.
The nunchchuck is fun too especially if you just want a different feel, rather than competitive gaming. I used it a lot for Atari, Game Boy, NES and SNES, in various configurations. For Atari usually directions with stick in left hand and fire button on one of the Wiimote buttons in my right hand. But I also played some games with one hand with the fire button mapped to the nunchuck. Even occassionally played NES this way, one handed with both A and B mapped to the nunchucks buttons.
I have a solid gamecube controller on hand but never end up using it because of these other options. Part of the joy of this setup is playing old consoles wirelessly.
I experimented unsuccessfully with a cheap 3rd party SNES-Mini control pad. There was lag issues and it also seemed to interfere with the Wiimote's normal function. But OEM might work better.
Edited by gliptitude, Tue Mar 12, 2019 9:35 PM.