Royalty free music libraries?

The license for our music library is coming up for renewal so I thought I'd ask here to see what others are using for royalty free music libraries. Atomica?

Aside from a local studio for custom commissioned pieces, I have no problem using Audiojungle, or even the cheaper alternative with an Envato Elements subscription. Obviously you have more chance that people will hear the piece used elsewhere but it all depends on the client and budget doesn't it?

I use Smartsound because each piece can have many customized variations but, on the other hand, the selection, although always growing, seems somewhat limited. 

Thanks for the suggestions. We've gotten used to having access to stems and/or mix variations which allows for a little more control over texture and can provide some variety. Smartsound's approach looks interesting. I did a quick search on Audio Jungle/Envato but didn't see any alternate tracks that weren't just different lengths.

Audiojungle do have what they call 'music-kits' which is a growing section.
audiojungle.net/category/music-kits

Try PremiumBeat.com
They've got stems for virtually all of their archive - haven't found a track yet that didn't.

For non-commissioned music, I use Artlist.io (which does not offer stems), and for certain specific genres, Fesliyan Studios.

The latter, at fesliyanstudios.com, operates on a pay-any-nonzero-amount-that-you-wish licensing, and they offer stem files on request.