I have all of the Miles Davis essentials, obviously -- Bitches Brew, Kind of Blue, and Sketches of Spain, as well as some other miscellaneous ones. I have a great Louis Armstrong collection, but I could always use more and I never know where to start with him. I have a bunch of early big band stuff too, from Cab Calloway and Duke Ellington. In terms of new (or nu, I guess) jazz, I have that These Are The Vistas by The Bad Plus and Jaga Jazzist's new album, but not much else.
Based on everything I have, what direction should I head towards to collect some new material? My favorite is definitely Cab Calloway's music and Davis' Bitches Brew. One-Armed Bandit is wonderful too.
edit: Oh, I have a bunch of Nina Simone as well.