1. Jon Jones Vs. Dan Henderson UFC 151
While all the other entries on this list are examples of a fight being cancelled because one fighter had to pull out, this one goes one step further and ended with the entire event being cancelled. UFC 151 was scheduled to take place in Las Vegas on the 1st of September 2012. Outside the main event, the card featured several talented fighters including Jake Ellenberger, Dennis Siver and Abel Trujilo. A bout between the incredibly talented Jon Jones and former-Strikeforce champion Dan Henderson for Jones light heavyweight title was set as the main event. Though being vastly oversized by Jon Jones, many believed that Hendersons strengths of excellent wrestling and dangerous knock-out power posed a genuine threat to the young champion. Henderson who was coming off of an impressive decision win of Mauricio Shogun Rua in what is widely regarded as one of the greatest fights of all time was forced to pull out of the event eight days before it was scheduled to take place due to an injury sustained to his knee. A replacement for Henderson stepped up to take the fight in the form of pound-for-pound trash-talking-king Chael Sonnen. Jones, however, refused to fight Sonnen on eight days notice after taking the advice of his coach, Greg Jackson, who said it would be a huge mistake. Thanks to this, many fans were left disappointed and the UFC lost a lot of money after promoting a PPV that never happened. His refusal to take up the gauntlet thrown down by Chael Sonnen heavily damaged the light heavyweight champions image, to the point where even now he is extremely unpopular for a fighter who is so talented and so consistently entertaining. Indeed, the UFC and Dana White has always cultivated the image that the UFCs roster of fighters are willing to fight anyone, anywhere, anytime; this image was heavily expounded by the likes of B.J. Penn, Randy Couture and, the man of the hour, Chael Sonnen.