Best Jazz pianist

They are all excellent and each have had they're special moments.
Steve Lawrence relayed a story about being a guest at a club in Europe with Fran Sinatra.On stage,the piano player asked Frank if there is something special he would like to hear.
His reply was Oscar Peterson but he's not here.
I'd like to add Vince Guaraldi to the already mentioned greats

Was there anyone before Monk & Ellington ?

Keep me posted & Happy Listening!

Oscar Peterson had a lot of soul , Canadian soul is just expressed in a different manner than ours .
Put another Canadian in there, Paul Bley .

Oregonpapa,
Whence I  first  became really interested in jazz I was naturally  drawn to the  big and established  names. So it was a lot of Oscar Petterson, I like him. Later on I discovered Thelonious Monk. I wouldn't say Oscar lacks soul but he doesn't move me as Monk does, just an entirely deeper  level. Natural evolving process with added time, lisstening and  exposure to this wonderful genre.I respect Petterson but have  the highest admiration and love for Monk''s playing and equally for his fabulous compositions. There is a profound emotional  connection with Monk that isn't  evoked with Petterson. Purely  subjective  obviously as we're  discussing artists of enormous talent with different  appeal.
Charles,

To me there's no single best. These days I would probably put on Bill,Evans, but by next week, I could have another firs choice. 

Enjoy the music!