Greg and Duane Allman.
Greg was one of those annoying idiot savants--He couldn't even stay married to Cher for longer than a forgotten weekend--with a perfect voice. And a perfect face. Not a good combination. Duane, just a perfect musician who died way too young.
Plus, I have this theory that Duane Allman was one of the best musicians of the 20th century. Damn those motorcycles.
If that isn't enough, just above is a clip of Duane and Eric Clapton playing the same song. Duane does a much better job on guitar than in the earlier version with his brother; Eric Clapton is a fine fresh fellow, but to compare his vocals with Greg...not going there. There's not a single live version available, so please put up with the sound, only--well worth it. All of you with stereo, listen, intensely, to Duane's slide guitar emanating from the left speaker. Heaven.
A bit of a personal recollection. I remember on our second date geebee (my sweetie) was astonished to discover that I was a huge Allman brothers fan. Of geruning course. No one better.