Having played briefly in the 70's and watched a lot of ball in the late 50's and in the 60's, I feel that Luis Aparicio was the best fielding infielder of all time. He could make outs out of balls that other shortstops couldn't even knock down---and make it look easy. Brooks Robinson was good, but 3B is a relatively easy infield position to play (SS is hardest, then 2B, then 3B and good stick-no gloves are hidden at 1B).
The best fielding outfielder ever would have to be Clemente.
The best defensive catcher was Yogi Berra. He could block the plate better than any other catcher.
All my opinions of course.