I've been on a big Thelonious Monk kick recently. It's been said that pleasure lies somewhere between boredom and confusion, and Monk's music illustrates this well. His fat, frquently dissonant chords along with his broken syncopated ryhthyms are never quite what you expect them to be in jazz from this time period. At the same time, his music remains the theory-heavy, quinetessentially cool type of jazz that I love from this heyday.
I think that every thing I love about Thelonious Sphere Monk is best put on display within a solo piano context. In the absence of a full rhythym or horn section, Monk's hyper-rythymic style becomes particuarly interesting structually as he provides the rythym, accompaniment and melody.