Difficult Classical Piano pieces - and one for fun

[Brus]

As someone who took (classical) piano lessons as a kid, I was interested in some online discussions I found about the most difficult pieces to play.

Here are two, and yep, they look damn difficult:

Feux Follets (Transcendental Étude No. 5) by Liszt, performed by Evgeny Kissin

Piano Concerto No. 2 by Bartók, performed by Yuja Wang

And the one for fun - Liberace plays an underappreciated "classic"

Liberace