As is most often the case in a romance novel, one or both main characters is considered an impossible catch. Hero or heroine, this particular lead is often regarded as the cream of the crop, the tip of the top, and the best of the best. He’s the most eligible bachelor. She’s the rarest diamond of the first waters. And so forth.
Why is this? I believe it is because the allure of catching an "impossible catch" is too great to pass up. The impossible catch is a huge draw for readers, myself included. The best books walk the fine line between impossible and actual, and your heart quickens with the leads as they fall in love.
Generally speaking, if the impossible catch is the hero, he doesn't want to be caught. In fact, he strives vigorously to avoid any situation that might end with him at the altar. When he’s caught though, it’s what he most desires and that is very sexy.
If the impossible catch is the heroine, she generally has multiple options of marriage. She's the belle of the ball. Her hero is not a good match for her economically speaking, but she doesn't care... it's his heart that matters most!
Some of my favorite "impossible catches" include Mr. Fitzwilliam Darcy and Elizabeth Bennet from Pride and Prejudice, Edward Cullen from Twilight, Mr. Edward Rochester and Jane Eyre from Jane Eyre, Mark Darcy from Bridget Jones, Justin Allistair of These Old Shades, and Sidonie Forsythe from Seven Nights in a Rogue's Bed.
Who are some of your favorite impossible-to-catch heroes and heroines?