This is unique in films of Hitchcock's that I've seen, in that I didn't really enjoy it.
In fact, I actually found this quite predictable and annoying.
Cary Grant and Joan Fontaine are a newly married couple. He's the kind of "lovable rogue" character that you've seen in many films, without ever being lovable as far as I am concerned!
In fact, it was a barely believable relationship at best, and at times seemed particularly false and implausible.
Unable to hold down a job and trying to live an opulent lifestyle, Grant is led to borrow money that he cannot pay back.
Fontaine is convinced that he is trying to kill her in order to get the money she is insured for; and presumably what her late father was worth.
Average and rather uninteresting all round actually, but as usual you can see the influence on films that have come at a later date.