Creeeeeeepy... *SPOILERS*
Let me preface this by saying that I think Alfred Hitchcock is one of the greatest directors of all time and I generally love his films. That being said, Vertigo is definitely my least favorite Hitchcock film that I have seen so far (and I have seen a bunch of new ones lately, I have been on a Hitchcock tear). The reason is simple: James Stewart as "Scottie" Ferguson is the creepiest AND most unsympathetic protagonist I have seen in a Hitchcock movie so far.
First of all, he for all intents and purposes seduces his friend's wife. The fact that she really isn't in the end is not important because she originally is in his mind. What a dick move. Then, after she supposedly dies, he harasses a woman he just met that resembles her into dating him and then bullies her into changing her whole appearance to match that of the "dead" woman. The fact that his suspicions about her identity are correct and she is willing to go along with it is immaterial. This dude is a creep. Worse even than Norman Bates from Psycho. I get the feeling that he would at least be civil to a girl on a date... well, at least until he took her home to meet Mother.
And I think the blame for this rests with James Stewart, who just didn't have the acting chops to pull of this character, who should have been portrayed as obsessed and neurotic but still sympathetic. Marlon Brando or Gregory Peck would both have been better choices to play this character.