The look of unabashed joy on his face after winning the Intercontinental Championship at the 1992 Royal Rumble, coupled with the deafening ovation from the crowd. You'd have thought he'd won the World Title that night.
His famous WrestleMania VIII match with Bret Hart, where, after teasing a heel turn (and wielding a ring bell at that!) he just couldn't bring himself to screw over his old friend. Bret ultimately wins, but the two embrace afterward in a very rare show of respect from Piper.
Piper was voted to be Ric Flair's partner at Cyber Sunday 2006, but had to be withdrawn from storylines a week afterward when it was discovered that he had cancer. Piper made a full recovery and credited the fans' vote as being what saved his life, as the routine pre-match medical check-ups were what diagnosed his disease in time.