What movies do you love the beginning of, and then at some point everything goes wrong? The one that made me think of this topic is Dune 1984. The beginning is amazing and I love it, and at some point, not quite sure exactly where, I start hating it. You got any like these?
It (1990). The first half is very good, sometimes brilliant, with overall good acting by the kids. The second half is a veritable disaster. It's as if the production ran out of money and talent!
It goes in the wrong direction in the last 30 minutes, but before that it's so excellent that I forgive it. Love the movie even with it's obvious flaw.
Most of Danny Boyles films fall apart in the third reel, until then they're pretty cool, he just doesn't know how to actually finish any idea properly without going off on some stupid tangent.
Full Metal Jacket. It starts out so good and builds in intensity. Then..... we are in Vietnam and it suddenly feels like another movie. I'm not saying it's a horrible movie. I'm saying that you are stuck in the middle wondering what the HELL happened?
I agree on Full Metal jacket the first half in boot camp is great, after that it becomes so uninteresting with the actual war.
28 Days Later: The first half is great, the second half with the soldiers is a completely different movie and loses my interest.
I Am Legend 2007 version: Despite the bad CGI, I really like it up until the 2 other people from Ireland show up and the rest just falls flat.
The Dark Half 1993: Great beginning, excellent looking and amazing atmosphere, then at the halfway point it introduces the killer and becomes unbearably cheesy, I couldn't stand it.
War of the Worlds 2005: Wow, the first 2 acts are thrilling, full of excitement and great scenes, then Tom Cruise ends up in a guy's basement and slows the whole movie down.
Those are the ones that come to mind, if I think of more I will add to it.
I felt that 'Die Hard with a Vengeance' really lost something in the second half.
The action just becomes ridiculously over the top and implausible. McClane's being blasted out of the tunnel on a jet of water, just as Zeus was driving by, was groan-inducing.