What makes this novel a favorite of so many readers after so many years?

Although I have read many articles and reviews on Pride and Prejudice, its perennial enchantment has eluded me until now. 

Not wanting to walk along the trodden path--"It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife"--I want to propose a few personal impressions. First, it is a syntactically and technically flawless narrative which is never boring; perhaps due to Austen’s adroit handling of the Indirect Free Speech (technique in which the reader gets into the character's mind without the narrator's help.)

Second, the characters are diverse: some attractive (Elizabeth Bennet and Mr. Darcy, Jane and Bingley). In particular, Mr. Darcy's attractiveness is impressive:

"The gentlemen pronounced him to be a fine figure of a man, the ladies declared he was much handsomer than Mr. Bingley, and he was looked at with great admiration for about half the evening, till his manners gave a disgust which tuned the tide of his popularity; for he was discovered to be proud, to be above his company, and above being pleased; and not all his large estate in Derbyshire could then save him from having a most forbidding, disagreeable countenance, and being unworthy to be compared with his friend"

Other characters are picturesque (Charlotte Lucas and Mr. Collins, Mrs. Bennet, and Lady Catherine de Bourgh). Austen regales the reader with pictures of her circle: the pedants, the immature, the cynical, and --yes, why not?-- all the idle at their best chitchatting and gossiping. 

The landscape is also overwhelming, especially to Elizabeth Bennett:

•  "Every disposition of the ground was good; and she looked on the whole scene, the river, the trees scattered on its banks, and the winding of the valley, as far as she could trace it."

Ah, Pemberley! If I could own it.

Third, that it is a moral work in which not only good manners and judicious decisions are privileged, but also virtue. Virtue that comes only after a few calamities:

• "The Bennets were speedily pronounced to be the luckiest family in the world, though only a few weeks before, when Lydia had first run way, they had been generally proved to be marked out for misfortune."

When Plato cast poets and artists out of his utopian Republic, little did he realize that one can learn virtue from literature as well as from philosophy.

Pemberly