This be the place to post any good & free Medieval/Renaissance themed online radio stations you can find. Here's 3 I listen to:
AOL Renaissance (http://player.play.it/player/aolPlayer.html?v=4.10.2&ur=1&us=1&id=890)
If you want to save it: AOL Classical Radio page (http://music.aol.com/radioguide/classical-radio)
Ancient FM (http://ancientfm.com/)
Live 365 Medieval Mayhem (http://www.live365.com/stations/mgt333?play=2)
Let the posting commence forthwith! ;D