Ooo. It's a hard question. Well, my favorite pianists: Oscar Peterson, Bill Evans, Chick Corea, Mecoy tyner
an recently i've been listening transcribing alot of keith jarret.
by the way, i was in Umbria jazz 2007. (the concert were he cursed the audience)
As the new member here, I'm probably going to go out on a limb with my choice of Paul Hardcastle as my favourite. His music just relaxes me for the most part, with an occasional jab of something out of the ordinary to see if you are still awake. Try his "19" for wake up music and see if I'm not right. My alternate choice might be unknown as well, anyone listen to Keiko Matsui?
As far as jazz with a guitar player that is huge, I love to listen to Stevie Ray Vaughan.
Rolling Stones Magazine put him down as the # 7 greatest guitarist of the top 100 of all time.
Classic Rock has his as # 3 of the Wildest Guitarists.
For any who do not know anything about his music, however, I find that hard to believe.
Here is just a bit of his music. Sure hope y'all enjoy listening.
I would have to say Oli silk. Best smooth jazz artist in my opinion. he has that Slow, yet loungey sound to his music and it also mixes well with today's modern music. his 2 latests albums "So Many Ways" and "The Limits The Sky" both have wonderfully composed songs from "Eve's Song" to "L` Austin's pace" they all seem to work well with the Urban or City look. Look him up on youtube and you will see what i mean.
So in my oppinion. Oli silk, best smooth jazz pianist EVER!