#1 Team WWE def. The Nexus (WWE SummerSlam 2010)

In mid-2010, WWE was in desperate need of a shot in the arm following various stars like Triple H, Shawn Michaels, and Batista ending their full-time careers. So when the eight rookies from NXT debuted on RAW and wrecked the arena, it sparked a major buzz. Suddenly, the road to SummerSlam became a very compelling one.
As the Nexus, these young upstarts were the focal point of Monday Night RAW. They attacked WWE Superstars and legends alike. Wade Barrett proved to be a formidable leader and was set to become a major player in WWE at SummerSlam, as his clan took on John Cena's team of WWE Superstars in a 14-man Elimination Tag Team Match.
The Nexus was built expertly, even without the fired Daniel Bryan. They were a proper shock to the system and it only made sense for Barrett to go over at SummerSlam. He would have been made, following a victory over a team featuring the likes of Cena, Edge, and Chris Jericho among others.
However, in the interest of having a 'happy ending' to SummerSlam, John Cena went over the Nexus. And the way he won left a really bad taste in everybody's mouths. Left in a 2-on-1 situation, Cena took a DDT from Barrett onto the exposed concrete and eventually rallied to pin Justin Gabriel and make the Englishman tap out.
This was a horrible decision, as the momentum of the hot new group was almost immediately squandered in favor of "sending the kids home happy". WWE tried to save the Nexus after SummerSlam, even booking Cena to join the group, but this defeat was too significant of a blow for Wade Barrett and co. to recover from.
This was Super Cena at his absolute worst, single-handedly burying the promising stable. Once looking like a certain future WWE Champion, Wade Barrett never won a world title in WWE. A real shame.