I must admit I haven't really looked up many professional players out there. Other than Jake Shimabukuro, Aldrine Guerrero, and a few others, I haven't been exposed to too many ukulele virtuosos out there.
Last week I stumbled upon a video of "Kiss from a Rose" played by Kalei Gamiao. I thought it was a cool arrangement and began working on learning it. Later I checked out another video of him playing his own composition called "Mach 4" and I was floored by it. So now I'm trying hard to learn that one too. Perhaps I'm one of the last ukulele fans to discover Kalei Gamiao's stuff, but if you haven't seen him play, check it out.