This movie is not only Hitchcock's best (just a tad behind 'Vertigo', in my opinion), but is one of the best movies ever made. Movies rarely have it all (story, acting, visuals, music, wit, action, suspense, 'hipness', and sexiness), but this movie has it all in spades.
Some of my favorite things about this movie:
1. Eva Marie Saint - Stunning...absolutely stunning. Everybody always thinks about Grace Kelly or Kim Novak in association with Hitchcock, but, for my money, Eva Marie Saint is the most drop-dead gorgeous of any leading lady.
2. The settings - The United Nations interior scenes are mouth wateringly rich. It really makes you want to go back in time to when everything 'modern' was new and exciting. We take so much for granted these days. The Cropduster scene is exciting and vastly more inventive than action movies being made today. Van Damm's House is the epitome of the promise that modern organic architecture once held. The scenes at Van Damm's house are even more amazing when you consider that the exterior settings are entirely fabricated, in a pre-CGI effects sort of way. They are more convincing than CGI scenes of today. Amazing.
This is one movie I never get tired of. Buy it and you won't be sorry.