Over the years I've tried a number of internet radio sites that allow you to create your own personalised radio stations that play only the music you like.
None of these however have come close to the quality and simplicity of Pandora.
This site is just so easy to use and the sound quality is so good that I use it all the time.
To create a radio station you just type the name of an artist or even a song and it goes away and finds similar stuff.
I'm now using this all the time to check out various acts without having to purchase anything or download anything.
I'm currently listening to my Frank Sinatra station, but earlier I was listening to my John Prine station and later I might try The Gotan Project or Shpongle.