Aznv.tv has a radio station which plays some nice music. Mostly music as heard in the drama's they upload. Unfortunately it's currently unavailable (I guess because of maintenance) but when the link is available I'll post it for you. Oh and the website requires an invitation to get in but the radio I don't think does.
My absolute favorite though is an Anime radio station from
AnimeNFO.. They feature mostly music as heard on Anime series (obviously lol). All the links provided there play the same station just in different bitrate (better quality) and in different servers. You'll need Winamp BTW
You can also always get something called the
LastFM Scrobbler. It's a nice little program like Pandora (if you've ever heard of it) which you can type in a keyword and it will play songs which fit that specific word like Asian, Kpop, Jpop and such. I recommend this program since I use it often

hehe
And speaking of
Pandora you can also sign up there and use their radio. It does pretty much the same thing as the LastFM Scrobbler but it doesn't require a download so you can play it right on your browser (also you can get it on your phone). I'm not to big a fan of it though because unlike the LastFM Scrobbler they limit the amount of times you can skip a song. So if your listening to a song you don't like and you've already skipped past your limit you're pretty much S.O.L.
Oh and one more thing

lol you can also find and listen to numerous Asian radio stations at
Live365. No subscription necessary (unless you want to favorite the stations you listen to) however many of the best stations are VIP which you can't listen to unless you have a paid account and they have commercials T_T but overall it's still pretty good.
Ok that's it lol