"Cut out the middle man." - Benny Hill

Probably the most under-rated source today is the ubiquitous AudioCD. I see them on the racks at many discount locations and I don't need to tell you how to convert them to MP3s or how to manage them. Cheep.

I also like iTunes and Amazon Audio. The Amazon player runs well on my devices and I can get such over the MP3 for that odd device or for other reason.

It's never been so wide open. Lots of good choices.