This is actually my first Roman Polanski movie, and I can see I've been missing out. Every frame of this movie is lovingly shot, with great performances all around (Olivia Williams as Ruth should get a Best Supporting Actress Oscar Nom) and an extremely solid script.
What's most interesting is that the technical prowess at play here gets pushed aside by the pitch-perfect tension that is present throughout the movie. For once, a Thriller depends entirely on razor-sharp tension rather than explosions; Ewan MacGregor's character slowly unravels the conspiracy that surrounds him in a way that is both elegant and captivating, reaching a great climax when you least expect it.
My only complaint with the movie, and the reason this gets a four, is the very end. It's certainly a fitting ending, and I can see why they went that way, but I felt it lacked closure, or that it wasn't sufficiently emphasized. It's hard to explain without spoiling anything, but although the ending kept me thinking about the movie a long time afterwards, I'm not sure it was the best possible one they could've gone with.
Regardless, an intellectual treat.
In a sentence:
Technically precise, artfully exquisite and intellectually thrilling, but concludes in a way that might not fully satisfy some viewers.