Nirvana @ Reading in 92, immense show, Rage Against The Machine @ Glastonbury in 94, followed very closely by the Beastie Boys at the same event. RIP MCA!
Special mention for the Prodigy too for their show at Cambridge Corn Exchange in 95 - on thw way to it I wasn't sure how they owuld come across live, but oh man they blew me away. Can still remember dancing like a nutter to No Good Start the Dance with a drugged up girl in hot pants and a bra with angel wings strapped to her back. fucking awesome.