Everything listed so far certainly has it's place, but I was blown away by the 9/14/98 RAW when going through the 1998 season recently. Flair returned on Nitro, so the Vinces drew up a card that was more stacked than most WWF PPVs were at the time.
Main Event: Austin vs. Shamrock for the WWE title (a match many had pencilled in for WM15 LOL), Taker-Mankind No DQ, Rock-Kane, Triple H-Owen, Edge-Gangrel, etc...everything was a blow off to a back story or a "dream" match or some sort. And for once, the in-ring action was actually very solid, with the title match going over 10 minutes for a change. Match-for-match, I doubt we'll find anything better until Feb 2000.