#1. Broken up too soon by WWE: The Nexus
The Nexus could have become WWE's biggest faction in the past decade. In 2010, they made an impact on WWE television, assaulting John Cena and several others on their debut.
The Nexus was actually a collective group of the original batch of NXT Superstars. This was, of course, when NXT was just a game show and not the company's developmental territory and third brand.
Wade Barrett was the leader of the faction, and the early days showed incredible promise. It took them no time to become the biggest heels on WWE television, and even without Daniel Bryan (who was released after his main roster debut), they were involved with John Cena.
Then Summerslam 2010 happened. The main event featured The Nexus vs. Team WWE, comprising of John Cena, Edge, Chris Jericho, Bret Hart, John Morrison, R-Truth, and the returning Daniel Bryan.
The objective of the match should have been for Barrett to pin Cena, defeating Team WWE and establishing The Nexus as the next big thing in the company. In a bewildering decision, John Cena decided that he was going to win the match for Team WWE, a call that most knew was incorrect.
Justin Gabriel, who was the second last man eliminated, recalled later that all of The Nexus knew that the decision was wrong. But since they were rookies in WWE, they didn't want to be pushy.
Their run would last until early 2011, after which The New Nexus was formed under CM Punk's leadership. By that point, it was far too late. In the eyes of many, The Nexus should have won the pivotal SummerSlam match and had a long run together - potentially establishing Wade Barrett as a main event star and benefiting some of the other members as well.