The UK-based MixRadio has the customary umpteen million tracks available, but it tries to be more personal than services like Pandora. It also seems a little less restrictive in what you can do with the free streaming music.
When you sign up for MixRadio, it has you choose some genres you like. Then it uses that to generate a list of artists you might listen to. As you go through and confirm your interest in various acts, the list will be updated with more options to better reflect your taste. Once you’ve given it enough to work with, MixRadio will build a few playlists for you.
The main “My Mix” is a mix of all the stuff you might like. You can like or reject a song to improve the mix. You’ve also got various artist-specific mixes and featured content. You can skip six times per hour on each mix, and there’s no skipping ahead or rewinding in tracks. This is similar to Pandora, however MixRadio lets you sync a portion of your mixes to the device for offline listening.