I like how Media Monkey will randomly pick songs to populate the current playlist.
After the current song is done, it will add another random song to the list. This way, you have constant music, can queue a requested song etc. but have a constant stream of music.
I hope I am missing this feature, but all I could find is the function that puts 3,5,10 songs in the list, but when those are done, it doesn't add new ones to keep the music continuous.