I need a hero!
Since the reader will see themselves as the heroine, you have to make the hero someone the reader wants to be with.
The hero should always be inwardly attractive. It helps if he's outwardly attractive too, but it's possible to have a scarred, deformed hero that we still love. (Jane Eyre for example, or even the Beast in Beauty and the Beast.) He doesn't have to be handsome on the outside, but he does have to have a heart of gold.
Most women still say the tall, dark, and handsome look is preferred. Taller tends to be more attractive.
Hair, skin color, race, eye color, and builds can vary. They need to take care of themselves, though. They don't have to be Mr. Universe, but they shouldn't be Homer Simpson either.
There is definitely a wish fulfillment aspect here. We want to be with the hot guy. We want to have the prince. So give your reader that if you can.
Your hero must be intelligent. Since this is a book, we only get a description of the physical but we get a play by play of what he says. He needs to have a brain or your reader will lose interest. If he's just a pretty face, why would our heroine (us) want to be with him? We'll be bored since we don't actually get to see those rippling muscles.
Intelligence, humor, and kindness will win the hearts of your readers.
The hero can be dark and brooding. He can be locked away inside himself with his emotions, or a bad boy with a dangerous past. He can be an assassin, a gangster, a soldier, a doctor, or a gigolo.
But he must be intelligent and have a good heart. Why would we fall in love with him if he didn't?