Steve Guttenburg has a lot of the same comedic sense as Cary Grant and does bear a little resemblence to him. George Clooney is suave, but I don't think he can do the comedy.
I'm not sure about bearing resemblance. I don't really consider him all that suave. He's more of the kind of guy I'd class as "nice guy" or "cutie pie". I wouldn't class Cary Grant as either of those. He could be goofy, but still somehow he made it look
good. Nobody talks like Cary... His voice can melt your heart and make your unmentionables twitter with orgasmic yumminess.
I'm mean, look at this delicious slurpy nom nom nommy sort of man: