I love the man. Everything I've seen I've enjoyed. Now, I have not seen his entire library, but I have seen many and was in a Hitchcock club about 10 years ago to try and get through his entire library. We did not make it all the way through, but today while surfing the internet I saw a post from a film blogger who mentioned a good "So you want to start writing Hitchcock" article. I do not believe this would be the order I would go, but it's as good as any. Take a look at this article, and really no matter how you go about it, just watch the man's movies. They are funny, thrilling and some of the best shot movies ever made.
In my group ten years ago, we tried to do a sort of Best Of but chronologically. We started with The Lady Vanishes which was funnier than I expected. Then moved onto Notorious, Rebecca, Vertigo, Psycho, Rope, then Rear Window.
I think we stopped around then, but I have seen a number on my own. Click on the link above in order to get to the article I read, but reading this made me want to go back and try and fill in some that I may have missed. I'm sure it will do the same for you.