well, I'm prejudiced because he was a friend of mine, but Al Haig, paritcularly his recordings from the early 1950s. He set the standard, and pianist like Tommy Flanagan, Barry Harris, and Hank Jones have all cited him as an early influence, as establishing an alternative to Bud Powell's sound. Also, Bill Crow has pointed out that Al was one of the most important musicians in establishing the chord changes on standard tunes, the changes used by most pianists that followed him. A great musician and a very interesting guy -