Some reasoning would be nice, but then again all you need to do is look at the card to see why.
Triple H vs Shawn Michaels in an unsanctioned match, with HBK making his epic return in a match I consider 5*. The story was great, the psychology was great with Triple H working on the obviously vulnerable back which had kept Michaels out for 4 years, and Michaels epic comeback and victory was awesome. Pretty much did everything that this sort of match should do.
Then you had a very good main event with Brock reaching the top of the mountain against Rocky, and a stacked card featuring very good matches such as Benoit/RVD, Un-Americans vs Booker and Goldust, Edge vs Eddie and the fun opener of Angle vs Rey.
The whole card was very good.
2006 to me was a disappointment. I enjoyed Foley/Flair but not much else appealed to me. Better than 2007 though.
2000 would be my pick for 2nd best. It was so memorable with the triple threat main event, the TLC, Benoit/Jericho 2/3 falls, the Shane bump, Kane being demasked etc.
*moved to old school*
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