In my book Little Richard and the Everly Brothers are tough to beat add Bo Diddley and wow.
Opening Acts For the Rolling Stones
One of the things I always admired about the band was their choices of opening acts. I speculate that early in their careers they may not have had much input, but starting around 1969 things changed. Here's a link to a website that actually lists every opening act since July 12, 1962 (Long John Baldry). I could be wrong, but I think Buddy Guy has done it the most.