Re: Most disappointing comic-book movie
Non-MCU: Spider-Man 3 or Wolverine 3: The Last Stand
MCU: Iron Man 3
DC: The Dark Knight Rises
Coincidentally, the above are all threequels.
Dishonorable mention: Ghost Rider or FF: ROTSS (Just because of how bad those movies fu**ed up Blackheart and Galactus!)
On His Majesty's Imperial Service