[FalconP]

The harp is best appreciated in a chamber-music setting, and the works by Debussy (sonata for flute, viola and harp) and Ravel (Introduction and Allegro for string quartet and harp) are justly famous.  I also very much enjoy Arnold Bax's Phantasy Sonata for Viola and Harp, as well as the chamber works by Toru Takemitsu -- which traces its lineage to both Debussy and Japanese traditional music.
 
There are some great compilations of harp concertos that have your usual suspects (Handel, Mozart, Rodrigo, etc) covered.  As for out-of-the-way works, I highly recommend the concerto by Alberto Ginastera: a latin-american infused work, pretty modernist, but is very exciting and enjoyable.
 
For folk harp, you can hardly get better than Patrick Ball, whose metal-stringed harp has a sparkling, bell-like tone.  The late Derek Bell of the Chieftains handles the music with unusual sensitivity and insight that betrays his classical background.  From Scotland we have William Jackson and his evocative original composions, while the exponent from Wales would be Robin Hwu Bowen.
 
Finally, if you like new-age music, the album Moai by Monica Ramos and the eponymous album by Emer Kenny are both beautiful and fun.  Hillary Stagg has been mentioned before, and I'd say the best place to start is The Edge of Forever.  Get the double live CD of Andreas Vollenweider if you have the chance.
 
 
 
 

 

[IPodPJ]

Andreas Vollenweider without a doubt.

 

[falis]

Joy Yu Hoffman "Blessings".  Chinese harp, very nice.

 

[zzffnn]

Thank you all for the great recommendations. I would add Lori Pappajohn 's Harp Dance
 
 

 
Amazon's Editorial Review describes the album very well:
Harp Dance features some of Winter Harp's most popular pieces including the rhythmic desert piece Caravan, and fiery Baroque Flamenco. From the ethereal sounds of the medieval instruments to the exotic mixtures of tabla and Celtic harps, the album will transport listeners to other times and places.

 

[DLeeWebb]

Andreas Vollenweider - His first three or four albums are amazing!

 

[spinlps]

On the Jazz side, check out Dorothy Ashby and Alice Coltrane. Plenty of hip-hop artists have sampled Ashby's work in their own.

 

[TJ Elite]

Cheryl Ann Fulton - The Once and Future Harp
 
You can listen to the album for free here. Amazon.com seems to have the CD version, and both AmazonMP3 and iTunes Store are offering the album as a digital download.

 

[zzffnn]

^ Thanks for introducing Cheryl Ann Fulton. I like her album of The Airs of Wales. The album you mentioned is also very good.
 
I will add John Doan as well, although what he plays is in fact a Harp guitar.

 

[Coldeign]

A little late, but I would highly recommend Rudiger Oppermann (similar to Vollenweider) and Edmar Castaneda, a truly genius in harp world music!