https://www.youtube.com/watch?v=tsxP-YjDWlQ (arioso from the cantata 156, here for oboe)
which I think stands up just fine against pretty much any other classical piece baroque or not.
Personally I have a very big soft spot for his organ works, as I play (badly) some organ myself, and among those I don't see the trio sonatas recommended nearly often enough (here is a live recital of all of them, which is super impressive)
https://www.youtube.com/watch?v=eK9irE8LMAU
among those I probably enjoy the most the vivace of BWV 530. Other favorite pieces are the passacaglia and fugue https://www.youtube.com/watch?v=nVoFLM_BDgs the toccata adagio and fugue in C major https://www.youtube.com/watch?v=Klh9GiWMc9U (the adagio especially is super nice), but there's so many. Among organists I often come back to Helmut Walcha, and am always amazed at how he was able to learn everything just by listening, him being blind.