#2 nWo and DX finally go to war
During the Monday Night Wars, the nWo was the sole reason why WCW was constantly beating the WWF in terms of ratings and in response to WCW's nWo, Vince McMahon and the WWF decided to come up with their own faction, the iconic D-Generation X.
Both DX and nWo were always known for their notoriety and with the two groups being employed by two different promotions, fans never actually had the chance of witnessing nWo and DX square-off in a Pro Wrestling ring.
However, all of that finally changed at WrestleMania 31, yes after all these decades, the nWo and the DX finally met face-to-face with each other in 2015 when Sting and D-Generation X co-leader Triple H went toe-to-toe in what was Sting's first match in the WWE.
With the D-Generation X outnumbering Sting, his biggest adversaries from WCW, The New World Order surprisingly showed up to a huge reception at Levi's Stadium as we finally witnessed two of the biggest factions collide on the biggest stage possible.