Bret Hart vs Yokozuna at WrestleMania 9. Not necessarily because of the in-ring aspect of it but the fact that Hogan captured the WWF title to close off the show which could have been Bret Hart's moment. Also, the match was too damn short for my liking.
Randy Orton vs Triple H at WrestleMania 25 was also one of the worst main event matches in WrestleMania history. It was dull, dragged on way too long, and the outcome of the match was anti-climatic. All of it was built up to Triple H and Randy Orton finally beating the living hell out of each other but instead, we get a standard match with a lackluster finish.