If you like Wonder Girls, may as well try 4minute and HyunA's solo career (they all sound very similar--Personally, I think HyunA's "Change" is a pretty good song.
)
Oh, and if you like rap at all, there's this guy who's supposedly the best K-Pop rapper, Outsider. He's not bad. I like the backtrack he has on his most popular song.....which, I don't know what it's called, though, sorry. ^^'