Best format delivery

Hi Chris, in your experience which is the best format mix file to deliver to digital platforms and why?

So we (my asst Will Quinnell and I) have found that sending 16/44 files to streaming services has worked the best. The less math they have to do to get to mp3 , Orbis or whatever the service uses is what we like. We always send the files back in the highest res delivered by the client as well so they can service Hi-Res platforms as well.