If you're in the mood for something less traditional but not quite "free", check out the Esbjorn Svensson Trio (e.s.t.). The founder of the group was sadly killed in a diving accident a couple of years ago, but the trio has left an amazing recorded legacy. My fave is "Good Morning Susie Soho", but it's terribly hard to find.
For an excellent mix of groove/jazz, check out MMW (Medeski Martin & Wood) or The Bad Plus. Both have done some very interesting covers, are a real blast to see live, and have uniformly excellent sounding recordings. In fact, I have been using MMW's "End of the World Party" as a reference disc for speaker design for years!
