The Little g minor fugue.
This is one of the simplest of Bach's fugues--no inversions, no augmentations, nothing else fancy.
But he fits a delightful subject with a delightful countersubject.
The d minor toccata and fugue.
This piece has been discredited for its doubtful authenticity.
But who ever did write this piece did a fine job.
The toccata is written in a recitative style, which is atypical of Bach.
But somehow the the composer makes those disparate parts fit together.
The fugue is written with an answer in the fourth instead of fifth, which is also atypical of Bach.
But it is a very moving fugue.
The passacaglia in c minor, with its unvaried theme repeated over and over, is easy listening.
Another melodically pleasant piece is his transcription of the Vivaldi G major cello concerto.