Mine is George Gershwin. I think he's an absolute musical genius. Masterfully blends the piano in with a full orchestra.
Rhapsody in Blue
http://stopokaygo.typepad.com/web/files/01_rhapsody_in_blue_for_piano_jazz.mp3
Rhapsody in Blue
http://stopokaygo.typepad.com/web/files/01_rhapsody_in_blue_for_piano_jazz.mp3