I'll nominate Brian May. I don't know if there's a more tasteful player in rock.
+1 on this. Just watched most of the new "Live At The Rainbow '74" show - what a beast.
Under appreciated? Even as a metal loving teen, Stanley Jordan amazed me. I always thought he should have been a household name for his talent.
Another +1. I saw him open for Wynton Marsalis in the early 80s. I turned to the woman I went to the show with and said, "I quit." Ended up going home and trying to figure out how the hell he was doing that. I don't know how he didn't get more recognition.
However, I'll add one off the top of my head - Mike Keneally.
Anyone who's ever seen him play live will understand....
Oh, big time absolutely!!! Huge Keneally fan here. When you look at what he's done over his career - solo (including his bands here), Zappa, Satriani, Screamin' Jay Hawkins, Dethklok...and keyboards for Chickenfoot??? What absolutely slays me about him (and Bryan Beller as well) is how seamlessly they can move from project to project. Mike may well be the best musician I've ever seen. He has streamed recording sessions in the past - during one, he was playing a solo and wasn't happy with the timbre of it, so he said, "Let me try it in a lower position." And then played it, first time, at full tempo - different position, different strings, different fingerings. No pause to check where everything was located or anything, he just ripped it off. Unbelievable. And I own one of his old guitars.
"Underappreciated" can be interpreted a couple different ways - underappreciated by the average person, or in guitar circles. I'll add just one with PRS ties - Davy Knowles. Unbelievably tasteful player. And gracious as well - as deserving as he is of commanding the spotlight, whenever I've seen him at Experience, he's more than willing to step back and let others shine.
