The first video that amazed me by the style of a SUP surfer was Kevin Coffman in 2010:
Not at all a longboarder style (no walking), but so smooth!
I would also to the already cited riders add Colin McPhillips, always a pleasure to watch, mixing classical and modern styles.
... And of course, Patrice Guenole' (Disclaimer: I am a Gong ambassador)
Who is such a noseride-addict that he even noserided a foil board!