Carlos Quebrada's Sales de Baño ("Bath Salts") sextet is what more jazz ensembles should aspire to be like. It's jazz from Argentina that desires chamber music status, perfectly seasoned with calculated doses of dissonance, sophistication, and the avant-garde, to complement rather than overwhelm the underlying flavors. I suppose you could call it progressive, I just call it great.
Another gem found on Mr. Moklebust's page.
Favorite track: 30.