The great Soul Survivor, Solomon Burke:
Extra points for those of you who know who wrote this song. Burke's version was on his outstanding Don't Give Up on Me cd, which you can by here. Don't Give Up on Me is part of a recent trend of bringing soul singing legends of the 60s and 70s into the 00s with cover songs and new renditions of old classics. Think Rick Rubin and Johnny Cash done right by Stax and you've got the low-down on recent efforts from Candi Stanton, Bettye Lavette (raw f'ing soul), and Mavis Staples.
Fans of The Wire may recognize Solomon Burke from season 3's ending medley:
In yet another interesting Tom Waits connection (sorry, Waits is my favorite and I have to do this), the theme song for The Wire is written by Waits, as is the best track from Burke's return to the mainstream: Diamond in Your Mind.