The 'King of Instruments' is too easy to sound great.
Solo piano will always test your system and these Sonatas: K. 281, K330 and K.333 will test your mind.
Vladimir Horowitz, piano; DG 445517-2
My only quibble is that a mike was probably placed underneath the piano as at a concert and there is too much gee whiz, ain't my stereo great pedal noise. OTOH, the instrument has a wonderful tone and nothing need be said about Horowitz.