The record for biggest disappointment in a movie I wanted to see goes to Peter Jackson's KING KING (2005)-- as a huge fan of the classic 1933, the not so classic 1976 and even the laughable KING KONG ESCAPES (1967) I was excited to see his take on the film.
Jackson was a self admitted Kong fan and I thought-- FINALLY we'll get a remake worthy of the original-- in fact what we got stands below KING KONG VS GODZILLA (1963) or even KING KONG LIVES (1986) in which Kong gets a heart transplant and is brought back to life to meet Lady Kong!
It was even worse than the Korean version from the 80s with the Mom from the Alan Thicke show-- at least that one wasn't boring.
Jackson's remake was overly long, overly sentimental and he didn't get the most basic thing right (No, not never casting Jack Black although that's a close second) he didn't get that Kong is a prehistoric Gorilla, he's not a Gorilla like you'd find in a zoo today. By having him just a normal (albeit 30foot) Gorilla is like having the dinosaurs be lizards with horns pasted on.
Kong looked like a 55 year old man with a beer belly, and although I give him credit for keeping it set in the 30s, it was an abysmal boring mess.