I'm gonna tentatively say Cloud Atlas, but I don't think it's terrible. I am aware that not a lot of people like it, and I believe if the Wachowskis had followed the book, it would have been better received.
Cloud Atlas, the book, was structured in a way that was easier to follow, and made for a narrative flow through its seven timelines. Seven timelines in and of itself is quite a tall order, but the point was that kindness and art resonate through each timeline. In the book, the first six timelines are told halfway through. At around the halfway point, you jump to the next timeline. When you get to the seventh, it plays through in its entirety (I think — I feel like the epilogue, if it was in the book, would have gone at the end — I haven't read the book yet, but it's on my list of books to read. I'm just aware of how it's formatted). Then the other six timelines finish, but this time in reverse order. So if the timelines are 1-7 and the halves are A and B, the book is basically 1A, 2A, 3A, 4A, 5A, 6A, 7A, 7B, 6B, 5B, 4B, 3B, 2B, and 1B. That makes sense. The film takes the book, cuts off the spine, throws all the pages up in the air, picks them up in random order, and then that's the screenplay. It jumps all over the place without rhyme or reason. And it's three fucking hours long!
The first time watching Cloud Atlas, I don't think anyone liked it. But once you know what's going on and you go back and watch it again, that second time, you know what all the stories are, and you're not getting thrown around as much. If I had the budget to adapt the book, I'd probably do it as anime and have 14 episodes, and you can see above how I'd do it. So each half would get a single episode. You'd be kinda lost for the first half, but then going through the second half, everything just clicks. I'm not sure how I'd do it as a film, except to say I fucking wouldn't. That the Wachowskis made it work for those of us with the patience to sit through a second and third viewing is kind of a miracle. At the very least I'd want to do a miniseries.
Cloud Atlas was not objectively terrible, but it was objectively flawed, and deeply at that. I still love it.
Also, Robin Hood: Prince of Thieves. Widely hated for Kevin Costner not being able to pull off an English accent and director Kevin Reynolds letting him get away with it. And yet, I don't think if Reynolds had recast Robin, it would have been as good. So if you look at the guys who were active in movies in 1991, you got some choices. Richard Gere probably could have pulled off the acting part. The machismo of Robin Hood? Of that Robin Hood? Maybe not. If you go with the classic Peter Pan-built Robin, and get rid of the war hero opening, maybe — but then how do you explain Morgan Freeman's character? And you don't write him out. There were plenty of actors who could have done the English accent and the action scenes, but there's something about Kevin Costner, American accent and all, that really tied that movie together. And it's kind of bad, Robin Hood with an American accent. I mean, what even is that? And yet, I love it.