Some would argue WrestleMania 17 was the most brutal and most entertaining match they put on, I would give it to WrestleMania 19. Both matches were great, and the latter could be seen as inferior due to Austin's injury which forced him into retirement, but the ending to the former match is, at least in my eyes, anticlimactic and a rehash of the ending to WrestleMania 16, and despite the handshake between Austin and McMahon being meant to signify the "end" of the Attitude Era, it just made for an awful ending (both in execution and in storyline) and an Austin heel turn nobody asked for.
Rock vs Austin at Wrestlemania 17.
My favorite was the WrestleMania 17 encounter.
WM15
WM19