Team Hulkamania is gonna' go maybe off the board a bit here, and with the first pick from the Storyline category, we select:
Stone Cold Steve Austin Feud with Mr. McMahon (late nineties).
It's amazing anything could make a guy (and I'm talking about myself here) go from absolutely hating a guy (Austin - during his feud with the then heel Bret Hart......I still remember going to the "In Your House: Canadian Stampede PPV" at the dome...possibly my fav. live event of all time, but I digress), to loving him, is pretty amazing.
The impact that this storyline had on the popularity of pro wrestling is undeniable...I think at the time the Monday Night Wars were in full swing, but I would argue this is the angle that really pushed pro wrestling over the top.
Anyhow, a good place to read a bit about it is the Austin wikipedia page:
http://en.wikipedia.org/wiki/Stone_Cold_Steve_Austin
Also, check out the video of Austin's first stunner on McMahon...MSG...New York...listen to what Mick has to say about it: