Great movie, no question about it. Of course, Hitchcock made 10 or so movies that I would call a complete masterpiece. By the way, its funny but my wife and I have seen several other Anthony Perkins films in the last year or so. In each of those films, at some point Perkins will flash his odd grin, and it immediately flashes Norman Bates in our heads. It's truly eerie, but my wife and I just start laughing about it whenever we see it.
Anyway, an excellent Perkins film that doesn't seem to get much notice these days is "Pretty Poison", with Perkins playing a variation on his Noman Bates crazy guy, talks a great game about doing crazy things. Problem for him is, in this movie he becomes friendly with Tuesday Weld, who is really off her nut. It's well worth seeing, and available on Netflix on DVD.