Mark Levine - teacher
I'm proud to say I got an "A" in Mark Levine's piano class for a semester I did with him at the Jazzschool in Berkeley. Mark literally wrote the book on jazz piano.
I had a nice Yamaha upright piano at my house in Oakland (which I sadly had to sell before I moved to the UK). But upon that piano I seriously worked on the material from Mark's class. Studying Mark's material and The Jazz Piano Book was a real eye-opener and gave me a better understanding of harmony and composition. Mark is a master jazz pianist with an immense and impressive discography, and it was great studying with him.