Ih-have-celestrial by Alan and Catherine Silva. Excellent jazz, modern classical, avant-garde, and other unusual tracks. Dig it.
Iridian by Robin Cox. Iridian's modern music is what first turned me on to the amazing potential of internet radio to satisfy every music lover's taste.
Mr. Poboy New Orleans by Steve Polatnick. Too much fun! Blues, Zydeco, etc.
81/80 Microtonal Radio by Jarod DCamp. Beautiful microtonal music.
Innova stations by American Composers Forum. Check out all the innova.mu stations for modern and international folk music.