Unlike famous guitarists or fiddlers, I've seldom heard a harpist in person, where I did not fall in love with their playing.
The guys:
Derek Bell of the Chieftans- a wonderfully fun performer & huge inspiration
Patrick Ball & Dennis Doyle
Robin Hew Bowen- master of Welsh tunes
The ladies:
Liz Cifani - Celtic to classical
Antoinette McKenna-lovely vocals & generous nature
Anne Heyman once upon a time

Lately the harpist who impresses me most is Loretta Simonett (of Curtis & Loretta) who can do tunes with the best of 'em, AND writes songs of great depth and beauty with the harp as lead instrument for her warm singing. She also has the advantage of being among the living, unlike Bell, McKenna and my Cleveland friend, Jocelyn Chang, who was an incredible teacher, and proponent of the Dilling Harp. Jocelyn was also known for her performance costume, a visual joke of mine: a Chinese dragon robe infused with tea imagery. I was just finishing a third edition of it, after she'd worn out the first two, when she died.

Tangentially, a harp of Jocelyn's was the cause of one of my favorite adventures. In the 90s, she paid me to bring back an $11,000 antique concert harp from Lyon & Healy's repair in Chicago in mid November. I visited several friends, taking the harp in with me at each place. The chance to see friends Lou & Peter Berryman in concert was irresistible. Peter came out to help me bring the harp in, past the line of folks going in to the show. "Peter, is there something you've added to your presentation?" They wanted to know. Then after, end of the night, hauling it down the street at Kate Early's place was entertainment for the headbangers leaving a nearby venue. Not entertaining was getting it up three tall stories.
      Next morning, heading home to Cleveland on a clear, cold day, I was a bit annoyed at the snarking about the Cleveland weather on Chicago NPR. By the time I got to South Bend, the er.. harping...about Cleveland on the radio concerned me enough to call my dog sitter for a report. "Everything is closed after a weekend snowfall of about three feet of snow. Plows haven't kept up. Don't know if you can even get up your street" Jocelyn insists her street is passable, they've all been shoveling, so come on. The weather grew steadily worse and snowier all through Ohio. The piles of roadside snow higher and higher. It was an incredible relief to get the harp intact to Jocelyn. The snow was waist high and unplowed at my house, and I waded bootless to the front door, only to find I had no phone ( for a week). It was days before I saw my dog again and longer before I got the car off the street, after it was plowed in. I got off easy: thousands just south of me lost power, some for over a week.

Joanne in Siberia on the Lake, where we THINK we're done with snow for the spring