When I wrote my first manuscript, I created the perfect hero. He was, of course, tall, dark, and handsome. He said the right things at the right times. He never had an uncharitable thought. He only took action when absolutely necessary. He was perfect.
He was also extremely boring. Three chapters in and I was already tired of this paragon of merit. And if an author is tired of a character, her own creation, you can be assured readers will be too.
Contrast that with Philippe, my hero in Breach Of Trust. Philippe is dark and handsome, sure, but he's short, very short, Napoleon short. He also has some of Napoleon's not-so-great personality traits. He's arrogant, bossy, and has the tendency to be selfish. If he had the power to take over a small country and declare himself its supreme ruler, he would.
He is imperfect, deliberately so. Because I noticed that all of the great romance heroes are imperfect. Mr. Darcy, in Jane Austen's Pride And Prejudice, is proud. He says some awful, arrogant things to Lizzie. Sebastian, in Loretta Chase's Lord of Scoundrels, his son hits (and almost everyone else) horribly. Lisa Kleypas' Sebastian, in Devil In Winter, is extremely vain.
This makes them interesting. They give the reader a reason to read on. Why are they that way? Will they change? If they do not, will the heroines love them despite their faults? Why would the heroines accept or even declare these faults?
As an author, you should answer these questions. Ideally your answers should be spaced through the novel, woven into the plot. Sebastian in Devil In Winter is slowly, painfully beaten of all the wonderful things feeding his vanity. Vulnerable, he is forced to take a long, hard look at himself. And we, as readers, fall in love with him as he does so.