There were two for me.
I never really got into wrestling from the show, I got into it from playing the games, but I was aware of all the major names. But never had Sky so I couldn't watch it. I eventually bought a video, which was the 'Best of Raw' 1997, and was essentially from Owen Hart vs British Bulldog for the European Title (it's debut as a belt) to Bret Hart knocking Austin off the stage after Wrestlemania (Taker vs Bulldog, Owen interferes, and Austin chases them off then goes after Bret in the wheelchair). And none of the matches were especially brilliant although I remember being really upset (I was 7), when Austin was breaking Bret Hart's leg.
So after buying this I bough No Way Out 1998 on tape, which I loved. I was a huge Kane mark (from Warzone), and him vs Vader I loved, but the main event, unsanctioned anything goes, HHH, New Age Outlaws and Savio Vega vs Austin, Owen Hart, Cactus Jack and Chainsaw Charlie, was my first real taste of the attitude era, and the promo's with the Foley and Funk going off the stage in the dumpster is still the most prominent segments ever for me, just J.R's screams, "There's People in there! There's people in there! What the hell is so great about that!" makes the whole thing.
That whole build up and match made me a big fan, but the one that really made me a huge wrestling fan was The Rock vs Austin at Wrestlemania 15. From HBK's promo against Vince, the referee's taking beatings (Rock Bottom, Chair shot), the two Stunners, fighting up the ramp. It was the first match that I loved for technique and storytelling rather than hardcore spots or just being a mark for one character.