In June of 1999, the opera singer Plácido Domingo received the longest standing ovation on record – 80 minutes – after performing Otello in Vienna. To put that in perspective, here is 2 minutes of applause for Bill Clinton (a mislabeled, but adequate, example). Domingo also received 101 curtain calls with his ovation, though the highest number of curtain calls belongs to Luciano Pavarotti, with 165.

I originally learned this from a BMW print ad, go figure.