How many of those allow you to keep the music if you leave them?I have offered up idjpool.com before and think it may be apropos here. The have most new music and have kept what they have online for many years, so there is a back catalog. They even have an oldies section, though that is sparser since they can only post re-releases they are given.
Another one that is a little cheaper but also has some older material AND video, is BPM Supreme. They run about $20/mo or $30 for the premium version.