2001: Britney Spears, 'N Sync, Aerosmith, Mary J. Blige... and Nelly
I mean, to me, everything about this is perfect. From Justin Timberlake's dance at the beginning to the moment at 2:10 when Nelly scurries onto the stage out of nowhere, it's the platonic ideal of a garish, inexplicable halftime show. It also should never have happened.