Wrestlemania 17 with Hogan/Rock 2 was a damn good event. It had the 3 Way Tables, Ladders, Chairs match and Shane McMahon vs Vince McMahon. And the Gimmick Battle Royale.
19 was great too, in Seattle... Lesnar vs. Angle, such a great match. Lesnar totally botched a Shooting Star Press, landed so crazy on his neck... then won. Austin vs Rock 3 happened there too... Hogan vs McMahon... Shawn Michaels vs Chris Jericho. Some good stuff.
There are a lot of great wrestlemanias.