Underrated jazz greats

I listen to all sorts of music, but mostly jazz. There are many musicians who, for whatever reason, don't attract the attention that their great gifts possibly deserve. I would be interested to know who others think are hidden gems in the jazz world, who have contributed substantially to the genre.

I will begin with two musicians who I believe are outstanding, and deserving of the highest recognition.

1) Lew Tabackin - an outstanding tenor player, and a phenomenal jazz flutist in my view.

2) Sir Roland Hanna - tremendous command of the keyboard, and he thought around the perimeter of pieces to make them both musically and intellectually satisfying.

Very interested in others' thoughts.
When I lived in Berlin in the 70's a lot of black artists lived there because the freedom from racism was exilirating.
thanks to all for posting - I never suggested that Tabackin, Roland Hanna and Paul Desmond were not recognized in their genre, only observe that they get less attention as unique voices in jazz than they maybe deserve.
I know many complain about the new Audiogon but I hope that people remain involved if only for threads like this which are invaluable for discovering new music. Thanks to all for posting. I will be purchasing several CDs or LPs based on this thread.
How about abdullah Ibrahim. If you can find it, Water from an Ancient Well. Great compositions ( Ibrahim is an Ellington disciplle), terrific band and outstanding recording.
'Water from an Ancient Well' is available on Amazon. Ibrahim was A.K.A. 'Dollar Brand'. Check under both names to see all his stuff.

Some people are not so much underrated, as they are not popular. And this can be for various reasons. Appearance, age, gender, race, style of play etc.... But the guardians, the enthusiasts, the keepers of the flame so to speak, they know!!