I think the thing about Hugh Grant (and I'm actually writing an essay about him this very moment for a film course - I'm distracting myself with more discussion about Hugh Grant... at least it's helpful) is that he does play the same kind of character in every movie, but we know that that character is funny and charming and so we don't really mind. Can you ever imagine him being an American cop? Maybe he's not a good enough actor, maybe he knows his fans wouldn't like it or maybe he's just too British. I think it's the familiarity with his acting that makes him popular, we know it's the same but we know it's also bloody funny so we don't really mind. It's worked for him so he's stuck to it. Some people will criticize (and I suppose for good reason) but he's popular enough that it doesn't matter.

(I've watched 4 of his movies in a row and Notting Hill twice I've definitely noticed the pattern lol)