Mine is Wrestlemania 20 even though I still haven't seen the whole thing. Eddie Guerrero with the title after it finished and him and Chris Benoit celebrating in the ring after the show with those papers falling around everywhere, one of the best Wrestlemania moments in history. And of course WWE's best ever triple threat as a main event was just precious. I've seen enough awesomeness in that ppv that when I finish watching it, even if some of the parts suck, nothing can ruin the class A stuff I've seen so far.
What's yours? And let's count in every promotion, I kinda think that most of the top 25 ppv's of all time are not even a product of WWE, at least for me since I prefer wrestling over entertainment.