Music doesn't get a lot better for me than Shokichi Kina & Champloose; in particular their live album CHAMPLOO! is one doozy of a listen start to finish. Okinawan pop mixes in the traditional sanshin (local version of the Japanese mainland's shamisen, this one is gentler sounding and uses snakeskin instead of leather or dogskin), vocal techniques, and kakigoe (II-IIYASASA) background vocals with rock instrumentation. The vibe at its livest can be like a folk version of 3d wave ska, but also with mellower moments (Kina's Red Puppy album).

Here's Kina performing the quintessential Okinawan pop song, his Haisai Ojisan (previous covered by YMO's *edit* Makoto Kubota, not Harry Hosono, to international acclaim, and also covered since by eclectic not-quite-supergroup French Frith kaiser Thompson): http://www.youtube.com/watch?v=mIW_yeZMxtM - 3:31 of insanity on wax.

EDIT: here's a '90s live version that sums it al up a bit better... actually, it's fucking insane, and even if you clicked on the first one and didn't like it, check this one out. And if you haven't clicked on the upper one yet, click on this one first anyway: http://www.youtube.com/watch?v=zc1j356uIbM&feature=related

this might actually be this first time I ever heard Kina's music... I remember catching a bit of a live show on TV in 1995 and having no idea who he was and not catching it from the program, then only putting the pieces together later after I'd been re-hipped to his music through other means.

That live record (CHAMPLOO!) is basically 75 minutes of this kinda stuff with a few slow songs thrown in. It's fucking great.
My interest in Okinawan pop grew out of an interest in mainland Japanese roots rock, and a lot of mainland bands used Kina's blueprint in forming their own sounds, especially in the wake of the Boom's massive 'Shima Uta' in 1992 or so: Shang Shang Typhoon, Bo Gumbos, Soul Flower Union, Zelda, Shisars, etc.

Other major Okinawan acts, while all worth checking out, never quite strike the balance that Kina does at his best. I've found several either cross the line into cheese (Rinken Band's bad synths overwhelm me despite their insanely catchy melodies) or adhere too closely to the traditional styles. That said, the Rough Guide to Okinawa (as well as its predecessor Rough Guide to the Music of Japan) is an excellent listen and several of hte bands featured have a lot of promise - if only it didn't cost $30+ to get their CDs on import.