Some names off the top of my head:
Charles Bradley (the screaming eagle of soul, a little over the top for my tastes but a good show)
Lee Fields
James Hunter
Sharon Jones
Renaldo Domino
Black Joe Lewis and the Honeybears
Not all of these are on Daptone or Desco Records.
There are more out there, consider this a starting place (and a number of these play the nightclub and festival circuits).
LOVE them. Michael Kiwanuka is someone I just discovered recently and I can't stop listening to his album. He has sort of an old school 60's/70's soul or R & B sound, although he does a lot of singer/songwriter type stuff, too.
Always Waiting - a very touching and haunting video.