In reply to wintertree:
I'd go back to 87 to re-watch New Order's headline set. I'd seen them in Manchester the year before at the 10 years of punk event and they were shite. At Glastonbury they were fantastic. Ending with a cover of Sister Ray, green lasers strafing the crowd while a feedback maelstrom filled our heads was something I'll never forget.
Ooh, and for contrast, Taj Mahal headlining on the Sunday. I'd never heard of him, but he was also excellent.