Bit of an obvious choice, but they're lovely pieces in the middle of an incredibly diverse and intense electronica album, and notable for how Aphex mic'd the pianos:
You could also link to some Erik Satie, given that's the minimalist piano ballpark Aphex was working within.
Thomas Newman's score for Road To Perdition features the piano (as does the film itself, in one great scene [https://youtu.be/60J7_sNbHBU?t=50s]) quite heavily:
And two with vocals, courtesy of Tori Amos:
Can't find a single upload of the album version, but here's the gorgeous Marianne [https://youtu.be/ErccRh9DGcg?t=19m25s] from the same album.