By Musician I am going to assume you mean a singular musician rather than my favourite band. As they vary quite a lot for me!
Ladies and Gentlemen, May I present to you, my favourite musician, playing his funky bass guitar:
Les Claypool!
In my opinion (yes it could be different from yours /shock /horror) the best bassist in the world. I actually wish I could play like that, and one day I WILL be good enough to play that song!
While I find my favourite band/s can change around a bit depending on what mood I'm in (although generally if anyone asks its Machine Head) my favourite individual musician will always be Les Claypool.
My favourite Musician is Gavin Harrison as I am drummer myself. He is huge inspiration for me as drummer and he is also a great person... He has great feel and everything he plays completly fits the song. I don't care about the flash other drummers are looking for as fast double base pedal or cymbal fencing. Funny thing is that he is winning a lot of "best progressive rock drummer" polls while he grew up listening jazz and never really tried to be a prog rock drummer or anything else but a drummer. He is member of band called Porcupine Tree (Which is also my favourite band), has experimental project with guy called 05Ric and played with a lot of different artist over the years.
Bonnie the Cat by Porcupine Tree. The actual songs starts around 2:55.
This song is in a 4/4 but sound like a odd time, vocals are quite strong pulse markers.
Sound of Muzak by Porcupine Tree.
And this song is in a 7/8, but it really flow thanks to his concept "overridding" with the quarter note accents on the hi-hat in first bar on the beat and in the second off the beat. In the chorus it is 4/4.
Here is a big band version of Porcupine Tree's song called Futile.
And this is a song from his experimental project with 05Ric (The Singer and guitarist, he played all the parts on the album).
Basically whole concept of this project is to use the strange drum ideas (There is also something about the harmony, but I am stupid in that area) that you can hardly use in "normal" music. But to a surprise it sounds rather groovy despite it being a mess of time signatures.