Where Can I get Unlimited Music Downloads?

I'm looking for a site/service that I can get Legal unlimited downloads, not streaming, for a monthly small fee ($10-15/month). Also, that if you ever do cancel you still keep the music.

I want downloads not streaming because a couple of the tablets we have aren't 4G just wifi, but would like to still be able to listen to the music on them when on the road.

Any suggestions? Anything that you have used and what are the terms of use? Every service seems to be unlimited streaming, but not downloads.

 

Example:

Microsoft's Zune service used to offer $10/month for unlimited downloads. So people don't download every song in the world in one month, the only catch was that 10-20 songs per month were premium downloads, so even if you cancelled your membership you did not lose those songs. Anything above and beyond those 10-20 gets wiped out.

 

Soulseek: http://www.soulseekqt.net/

 

Microsoft zune. I used to have one of those things forgot all about it.

 

I've actually got 2, still ticking. Mostly use phone/tablets now, but they still come on handy when running so I don't get my phone drenched in sweat. Never had their service though.