Of the pieces I used to play, my mom's favorite is the last movement from Bach's Partita No. 1 in B flat Major (BWV 825), the Gigue.
Unfortunately, I don't have a recording of the piece, so I made one for my mom's birthday.
It's a work in progress (both the playing and interpretation), but here's where I am, warts and all. That, and the recording quality is so-so, since I just stuck my phone near the lid prop.
You can look at all the birthday piano posts.