Literally watched it for the second time myself last night with my parents (their first time seeing it) and after a shaky start of them not being really into it by about half way they were absolutely glued and even commented how good it was when it finished.
It's incredible. A terrifyingly believable depiction of a broken man's spiral into insanity. One of the best "character studies" I think I've seen in a movie, closely followed by De Niro in "Taxi Driver".
