While there are loads of applications for playing Internet Radio and your own Music - I have yet to find a simpler and easier one to use than this one
The Internet Radio search is fine -- you can browse Music in FOLDERS (as well as albums etc etc) and it plays FLAC as well as almost any other codec without a problem).
It's basically the Logitech squeeze system -- but you can run this entirely on a Local machine without having to use any of the Logitech hardware devices.
You install the Logitech media server and the squeeze play (both applications are FREE) -- you don't have to have the squeezebox devices if you just want to use the application on a local machine. It will play in this case through the computer's audio system.
Saving complex opml addresses for Internet Radio is simple -- such as Boston's HD2 WGBH Classical music service and the search facility works to locate Internet radio stations from all over the world and save the opml data for the streaming.
Playing music by simply browsing local folders is fine too --particularly with Audio Books where you just store the name of the book as a folder within the music directory.
I've tried loads of different players etc but this one incorporates Radio and local music just fine (and if you DO have the logictech hardware streaming all over your house is easy too -- same interface on the handset).
Enc some small screenshots of the interface