To Catch A Thief is of course the 1955 Hitchcock movie starring Cary Grant and Grace Kelly. I confess to being rather ambivalent about it... on the plus side, it stars Cary Grant which is never a bad thing. Grace Kelly is beautiful- obviously- but her character does nothing for me and in fact is rather annoying. I suppose for me the movie's biggest flaw is that it's not the book, which I read before I saw the film for the first time (this is also why Shane is not one of my favourite westerns). The changes made by Hitchcock to the plot and characters were not improvements, in my opinion cutting most of the suspense and strong interpersonal relationships out of To Catch A Thief. What's left is a sleek, glossy heist/romance movie which has its charms but they are shallow, surface ones, lacking the depth- and actual mystery- found in the source material. Which, to bring this back around to my original topic, is why I did not previously own a physical copy of the film: I don't like it enough to buy it at full price. But for $2.50 in a thrift shop? Sure!
I actually reviewed the novel To Catch A Thief a few years back, and contrasted it in more detail with the movie; I'll provide the links below.