Of late, Dawson-Hopkins, but I didn't pay for it though so I obviously failed in answering your question
Here in the UK, I imagine not many people were happy when they paid £30 for Khan's SKY debut, and got 51 seconds for their money.
Never bought a PPV. I know the worst my dad bought however: Tyson - Seldon He never bought one again..
Pacquiao/Mosley....I should have know after Pacquaio/Hatton/Clottey/Cotto/Margarito that his PPV's weren't competitive. I will not buy a Pac PPV until he fights Mayweather or Martinez