Windows 8: PRadio is a free Pandora client for Windows 8 and Windows RT that brings your Pandora stations, likes and play history into Windows 8's Modern UI. You can pin your favourite stations right to the Start screen, or you can bring the app up to choose the station and let it play in the background.
PRadio gives you quick access to your bookmarked songs and other profile information, and makes it super-easy to change stations, thumb up/down tracks as they're playing and look back over recently played songs. Pinning stations to your start menu is a huge bonus, and search is integrated right into the Charms bar. As soon as you start typing, the app will look for stations that match what you're typing, or find new stations, artists or genres for you.