I don't see why Hart vs. Austin for the WWF Title didn't Main Event. Hart had a Blue reign as champion before losing to Sycho Sid for no real apparent reason. The crowd was eating Austin up, and Taker and Sid was dead after the crowd was drained out in the Hart v. Austin match.
Anyways, I think Lesnar v. Undertaker at WrestleMania 30 deserves some love. It started the biggest boom in Lesnar's career, that culminated in a WWE title win and a WrestleMania main event. It also led to some MOTYC in their match at Summer Slam (despite the horrible finish) and their brutal Hell in a Cell that October. It was also the most shocking finish in WWE history, and the only thing that comes close is Ivan Koloff beating Bruno Sammartino. The crowd almost tore that place down, when that happened.