My favorite late sonata is the 7th. My favorite middle is the 4th. My favorite early is the 2nd.
My favorite larger form besides the sonatas is the Fantasy, Op. 28.
My favorite late Etude is 65-3.
My favorite middle Etude is 42-5, although 42-4 and 6 are gorgeous.
My favorite early Etude is 8-12 Alternate, although I love 8-12, 8-5, and 8-9.