As I type, Shutter Island is #246 on IMDB's Top 250 movies of all time. I don't know about that. If you watch it, you may not know about that. It depends a lot, I think, about how you feel about the subject matter. But Leonardo DiCaprio stars, Martin Scorsese directs, and it's based on a Dennis Lehane novel. Those are all signs of quality.
DiCaprio plays Teddy Daniels, a U. S. Marshal assigned to an investigation at a facility for the criminally insane at remote Shutter Island, many miles out in Boston Harbor. He's investigating the disappearance of prisoner/inmate Rachel Solando, who has impressively busted herself out of the secure facility without anyone noticing. But, as it turns out, Teddy is also on a mission of his own: his wife died in a fire set by pyromaniac Andrew Laeddis, who is also supposed to be on Shutter Island, and is also inexplicably missing.
All this is accompanied by very suspicious behavior by the ostensible good guys: Chuck, Teddy's new partner (played by Mark Ruffalo); the doctors running the place (Ben Kingsley and Max von Sydow); a very creepy head warden, dressed up in an SS-like uniform (Captain Leland Stottlemeyer himself, Ted Levine, mustache-free). And every nook and cranny of Shutter Island is filled with ominous ugliness.
I didn't know much about the plot going in, but it turns on extremely vile and shocking behavior, and that kept me from liking the movie as much as I might otherwise. Your mileage may vary, or it might not.