#1. WWE's handling of The Nexus
The Nexus is perhaps the biggest "what if" storyline of WWE in the past decade. It was back in 2010 when NXT was still a game show and not a development territory like it is today.
The first batch of NXT stars "graduated" to the main roster, but as one unit. There were no mentors, and it was just a fresh set of young faces who essentially took over WWE.
A former WWE writer just went after JBL for his comments HERE
Their first target was the face of WWE John Cena, and their debut on the main roster saw them wreak havoc in the ring and at ringside — announcing their arrival. It first culminated in a SummerSlam main event, where The Nexus, led by Wade Barrett, took on the John Cena-led team WWE.
WWE fans felt that The Nexus needed the win to establish themselves as the top faction of the company, and also skyrocket Barrett into potential superstardom. That didn't happen.
Unfortunately, John Cena had cold feet about the idea of The Nexus winning. Instead, he lobbied for the finish to see himself facing the odds in a numbers game before eventually triumphing. It's a decision that seems to be unanimously viewed as a bad one, possibly even by John Cena himself in hindsight.
The second culmination of their feud saw John Cena defeat Wade Barrett at TLC 2010. In that main event, the night ended with Cena dropping a lot of chairs on Barrett to end their feud and almost literally "bury" him.