Ye gods. Quite a few:
Eric Burdon (w/o the Animals)
Crosby, Stills & Nash
Jimmy Page (w/o Zep)
Not all of those were as individual artist concerts. For example, I saw Newman, Browne and Ronstadt as part of a Steve Goodman tribute concert. Clapton, Page and Beck were all featured in the ARMS Benefit concerts. Although I later caught Ronstadt solo.
I’ve seen Neil Young, Santana, Bruce Springsteen and Fleetwood Mac both before and after induction.