I was thinking that I´d pick up Ravel´s left-hand concerto once more, a piece I´ve studied before, and was thinking about adding other left-hand works to the repertoire. Apart from there being several beautiful works for left hand alone, it is also very useful and developing to work on pieces focusing only on the left hand. What are to your mind the most interesting/valuable pieces in the left-hand repertoire?
I´d mention the following:
Scriabin - Prelude & Nocturne op. 9
Godowsky - several of the chopin studies written for the left hand are interesting in their own right, in particular the one made after op 10 nr 6 in E flat minor
Alkan - nr 1 from three etudes
Ravel is said to have studied Saint-saens etudes for the left hand while writing his concerto, but I don´t think very highly of them as musical pieces.