All three of Gilbert and Anne's sons could count, but especially Walter. Walter is noted as being the handsomest of his siblings, with "finely modelled features" and expressive gray eyes. On top of that, he's sensitive and a poet. Even in-universe, the girls adore him from childhood on. However, he is a little bit of a Clueless Chick Magnet.
It's also heavily implied (though not outright stated) that Crowley was originally the Serpent from the Garden of Eden, effectively giving him the mother of all dark pasts.
A good three-quarters of the book is Bella telling us how perfect and handsome Edward Cullen is.
He is also tortured over his thirst for Bella's blood/body and worried about taking away her soul, he remembers everything she likes, keeps complimenting her on her looks and perceptiveness, and pretty much does everything within his power to make her happy even if that makes him unhappy himself and he even learned to cook for her when he doesn't even eat!
Bella's dad lampshades it for Dr. Carlisle Cullen, saying that it is a good thing he's happily married and saying that the nurses have trouble concentrating around him
Twilight is basically a book series about this trope! We have the extremely ripped Emmett, the Troubled, but Cute Jasper with a dark past, and the the Ho Yay dripping Wolfpack! Even the movie version of James is fetish fuel!
Warrior Cats seems to have, well... almost every single male related to Tigerstar, because he seems to have the Mr. Fanservice gene (Tadpole didn't inherit it for some reason). Most people would probably never think of being attracted to them because they're cats, but Tigerstar, Brambleclaw, and Hawkfrost do have fans that think they're sexy.
Other characters who stand out are Whitestorm and Brackenfur. Apparently one of the authors even has a crush on Brackenfur.
Scourge also counts. He even has his own self-proclaimed fangirls who usually pair him up with their OCs, 99% of which are self-insert Mary Sues.
The Dresden Files: Thomas Raith is nothing but this. Also, judging by the descriptions, Sanya and Michael also qualify.
Adolin Kholin of The Stormlight Archive, described as handsome in story, Also Kaladin, judging by this thread on a fan forum. Mostly because he's tall, and both badass and a woobie. Also he glows.
Even without a movie, or even an illustration, Garrid still manages to be this for Tales of the Frog Princess.
Prince Jonathan of Conté from Tamora Pierce's Tortall series. Handsome, sweet, loving, handsome, gentle, kingly, handsome, responsible. Did I mention handsome?
Many of her male characters could fit this role. Neal, Dom, George, Nawat, Numair, Rosto (who definitely has his own Brigade in the Court of the Rogue). Most of these characters have quite a following in fandom as well.
Enjolras in Les Misérables is said to be this in-universe. Not surprising which of the students gets a significant fanbase.
Finnick Odair in The Hunger Games, in-universe. Of course, this series being what it is, this trope gets deconstructed hard when it's revealed that President Snow has been forcing him to prostitute himself because desirability = profit.
