Fellow #1: Hi, I’m a scoundrely rogue! The heroine will meet me first and be put off by my bad manners.
Fellow #2: I’m a polite and respectful gent who’s not afraid to express romantic interest in the heroine.
Fellow #1: Soon, though, you’ll learn that I have a HEART OF GOLD! This means that I’ll do something brave and self-sacrificing, but I still won’t stop being rude and inappropriate. Don’t worry, though – the heroine will come to find it charming.
Fellow #2: Meanwhile, my kindness will be revealed as a ruse. I’m actually straight-up evil. Doesn’t that make the first guy look good?
(Honestly, though, I see these two types so often that it starts to make me mistrust any male character who actually seems . . . well-behaved. Kind of unfortunate.)