[Sirius Lee]

Screw your wire bands! Everybody knows it’s the late Sonatas which kick ass starting with the Hammerklavier.

[Publius]

That's a bit extreme. The Late Piano Sonatas are wonderful, but the Late Strong Quartets are wonderful too.

Piano Sonata in A, Op. 101

Piano Sonata in B-flat ("Hammerklavier")
The slow movement has been described as "a mausoleum of collective sorrow."

Piano Sonata in E, Op. 109

Piano Sonata in A-flat
I saw Schiff play this in Vancouver. In the finale, Beethoven takes a common street song and turns it into something divine.

Piano Sonata in C Minor, Op. 111
In the final movement Beethoven invents jazz.