This might meet with some resistance on this thread, but I'm a big fan of how Bela Fleck is pushing forward and experimenting with new ways to incorporate bluegrass into jazz and fusion music.
No resistance from me on Bela Fleck. I've been lucky enough to see him in concert a few times. I've been blown away each time. Reminds me a lot of the bluegrass fusion that the Dead were doing in the 60's only less psychadelic.