One of the most amazing surprises for me when it comes to musicians was not really caring for Glen Campbell pretty much AT ALL until one time I saw him play a guitar solo and he floored me!
The man was a virtuoso on the guitar yet almost never put it on display.
As for 'shredders'... pretty much all of them amaze me because I don't have a clue how they do that.
But I have to admit....
Bass players, a few of them, amaze me the most. Some of them sound like their playing 12 different instruments at the same time.
I think I've mentioned before that I could NEVER say with certainty what my favorite instrument is... but I think I can say that the most 'pleasing' sound produced by an instrument is, for me, the Cello... with the acknowledgement that I like EVERY musical instrument... even Ramgators triangle.