Wrestlemania X-7. Austin and Rock put on the greatest match in the history of their feud (and one of the greatest matches in Wrestlemania history, too), Triple H and the Undertaker had a very good knock-down drag-out fight with each other, Benoit and Angle put on a pretty good technical match (though they've had much better, namely at the 2003 Royal Rumble), the triple threat match for the Hardcore Title was pretty fun to watch, loved seeing Chyna destroy Ivory (and destroy the credibility of the Women's Division in the process), the Gimmick Battle Royal was mindless fun, etc. It was a pretty stacked card and still the greatest Wrestlemania event in history imo.
Other events that I'd rank among my favorites: King Of The Ring 1996, Royal Rumble 2001, Summerslam 2002, etc.