For fighting games, my own custom built stick. Put this together last year to replace the Hori RAP4 that had served me well for seven years until a button cap broke off. Super happy with how this turned out. It's much lighter, I like having a detachable cable. GP2040-CE supports Switch natively so I no longer need an adapter (and I can feel the difference in latency now), and Sanwa silents mean I can practice late at night without keeping anyone awake. And it just looks good, it's on brand for me.
For everything else that is not fighting games, 8BitDo Pro 2.
I also have a soft spot for the Wii Classic Controller Pro, I miss having gates on the analog sticks. I'd kill for a modern refresh of that with L3/R3, gyro, and USB instead of having to plug it into a Wiimote.