I've never managed to find a Wii-connector-to-USB adapter that wouldn't inexplicably die within six months, but the 1st-party SNES Classic controllers are basically perfect clones of the original. Ditto the NES versions they have. Wii Pro Controllers are also great and have a similar feel & quality, but with modern ergonomics (no rumble, though, so not great for e.g. Playstation games, and IIRC the triggers aren't analog, which is limiting)

You can connect Wiimotes to PCs over Bluetooth and use any of those Wii-connector controllers through them, which would make them wireless and solve the finding-a-reliable-adapter problem, but I've never managed to make that kind of set-up sufficiently stable. Always having to screw with re-pairing and such.

In the end, my go-to for BT emulation controllers is usually a PS3/4/5 controller. I haven't tried the XBone but I found the d-pad on the XB and XB360 controllers unusably inaccurate, and the face buttons weirdly slow when trying to play old-school Nintendo-hard games. Playstation controller d-pads are much better, and the face buttons feel quicker to switch between, for whatever reason.