I really think it depends on the book. There are some really wonderful romance novels and then there are some of the cheesy kind. I admire romance authors who are original and books that are about more than just the romance. A favourite of mine is Atonement by Ian McEwan as it has such depth and underlying themes.
If a sex scene is appropriate, I don't mind. But if it is out of place or just there for the sake of it, I am not a fan.