Glastonbury regular, so seen many many great acts there (Dolly Parton, Tom Jones, Shirley Bassey, McCartney etc.. oh, and Muse, Radiohead, Stones, Verve, and Metallica of course)
Early days for me was Sabbath, Free, Rory Gallagher, Roxy Music
More recent Foo Fighters, snow patrol, killers, green day, and of course the Specials
Have to say, one i really enjoyed, but came as a complete surprise as I had heard very little of his music, was Damian Rice.
edited. forgot to add Queen. Amazing show.