Generally, they fall under Type 4-5 of the Sliding Scale of Antiheroes, depending on the tale.
1: A protagonist that is presented by the story as a charismatic hero despite some serious moral failings and flaws that usually would make him hated.
2: One of the protagonists from the writings of Lord Byron (who was himself a Byronic Hero)
Basically what I get from it is that he's the bad man that women want, even though they know they shouldn't.
edited 2nd Aug '11 5:56:06 AM by Sackett
Okay. Can you give one or two well-known characters who are exemplary of the trope?
Fiat iustitia, et pereat mundus.There are tons of these in Russian novels- Eugene Oneigin (of the novel-in-verse of the same name), Pechorin of A Hero of Our Time, Raskalnikov of Crime and Punishment.
Also, The Count Of Monte Cristo
Heathcliff of Wuthering Heights tends to be considered a quite good example of the character in English literature and kind of a lesson of why you actually wouldn't want to be anywhere near them.
HodorEdmond Dantes from The Count Of Monte Cristo
Lucifer in Paradise Lost according to some (despite Word of God to the contrary).
Sirus Black (the popular one) and Severus Snape (the unpopular one) from Harry Potter. Demonstrating together the very subjective nature of "heroic" vs "villainous" label for these types of characters.
The Other Wiki might help here.
edited 2nd Aug '11 8:42:20 PM by Sackett
I have trouble telling heads from tails about Byronic Hero's definition. It doesn't help that it seems to have a persistently recurrent history of Trope Decay, judging by its discussion page.
Fiat iustitia, et pereat mundus.