What do you love about Madame Bovary?

I studied literature and usually love reading classics. I just finished James’s Portrait of a Lady, and it’s one of my favorite books I have read in a while. Every character is complex and every moment is subtle.

But I’ve been reading them side-by-side, and in comparison, Madame Bovary seems simple and obvious at every turn. (I know of course that Madame Bovary was an influence on James, so maybe I’m not being quite fair.)

Is it just a matter of taste—or am I missing something? What makes this book great, in your opinion?