Jane Austen/Awesome

Northanger Abbey

When the Thorpes can't convince Catherine to cancel plans with the Tilneys for a scheme of theirs instead, John Thorpe goes and lies to the Tilneys and does it for her. Catherine promptly turns around and runs after the Tilneys to set the record straight, refusing to let tricks or lies cheat her out of what she really wants.
- It's better than that. If it was just for what she wanted, she might have done it, but she did it because of her morals. She refuses to break her morales.

Sense and Sensibility

Edward finally standing up to his mother and telling her to keep her money, he's marrying whoever he wants! And here we thought only women had to deal with Arranged Marriages...
Marianne, against every rule of etiquette in the book, defending Elinor from Mrs. Ferrars' Stealth Insults -- everyone else, Elinor included, is appalled... except Colonel Brandon, whose inward reaction can best be described as, "Wow, that's hot!"

Pride and Prejudice

Elizabeth's tranquilly furious telling off of Lady Catherine, when the latter essentially tries to bully her out of an engagement (which doesn't, at that point, actually exist) to Mr. Darcy. Having previously unnerved the woman in Kent by making it clear she does not worship her like just about everyone else who knows her, she now defends her right to marry whomever she pleases, and basically tells her to "Mind your own business!" Go, Elizabeth!

Lady Catherine: You are then resolved to have him?
Elizabeth: I have said no such thing. I am only resolved to act in that manner, which will, in my own opinion, constitute my happiness, without reference to YOU, or to any person so wholly unconnected with me.
Reader: GO ELIZABETH!

Mr. Bennet's letter to Mr. Collins, announcing Elizabeth's and Darcy's engagement: "If I were you, I'd stand by the nephew -- he has more to offer."
Mr. Darcy's selfless heroic rescue of Lydia's -- and, therefore, the whole Bennett family's -- honor, which involves negotiation to his own financial loss with his Arch Enemy. Elizabeth spends a whole page swooning over the awesomeness of it.
Mr. Darcy shooting down Miss Bingley's hopes once and for all when at Pemberley she is trying to bait him into criticizing Elizabeth as he used to.

Miss Bingley: I believe you thought her rather pretty at one time.
Mr. Darcy: (who could contain himself no longer) Yes, but THAT was only when I first saw her, for it is many months since I have considered her as one of the handsomest women of my acquaintance.

Elizabeth's refusal of Darcy's original proposal. Darcy, up until this point, has done nothing but acted like a total snot, and Elizabeth calls him out on it. Thus begins Character Development on Darcy's part, turning him into the guy that millions of women still swoon over.

Mansfield Park

The heroine Fanny Price, who has been pushed around and psychologically abused by the Bertrams and Mrs. Norris for years, finally stands up for herself and unequivocally refuses to marry Henry Crawford, against everyone's guilt trips and rationalizations that it's a perfect match. Those with a brain are eating their words later when Henry runs off with the now-married Maria Bertram-Rushworth. The confrontation with her uncle is particularly awesome not only because it parallels Elizabeth's refusal of Mr. Collins in Pride and Prejudice but because she has the double burden of keeping her love for Edmund a secret... and succeeds.
All of Austen's heroine vow to Marry for Love, but the Shrinking Violet Fanny gets the only explicit feminist speech in all of Austen when she insists on women's rights to use their own judgement and consider their own happiness rather than automatically feel it their obligation to satisfy the desires of any man who chooses them. It's borderline radical given the marriage market at the time:

Edmund: That you could refuse such a man as Henry Crawford seems more than they can understand. I said what I could for you; but in good truth, as they stated the case -- you must prove yourself to be in your senses as soon as you can by a different conduct; nothing else will satisfy them.
Fanny: (after a pause of recollection and exertion) I should have thought that every woman must have felt the possibility of a man's not being approved, not being loved by some one of her sex at least, let him be ever so generally agreeable. Let him have all the perfections in the world, I think it ought not to be set down as certain that a man must be acceptable to every woman he may happen to like himself. But, even supposing it is so, allowing Mr. Crawford to have all the claims which his sisters think he has, how was I to be prepared to meet him with any feeling answerable to his own? He took me wholly by surprise. I had not an idea that his behaviour to me before had any meaning; and surely I was not to be teaching myself to like him only because he was taking what seemed very idle notice of me. In my situation, it would have been the extreme of vanity to be forming expectations on Mr. Crawford. I am sure his sisters, rating him as they do, must have thought it so, supposing he had meant nothing. How, then, was I to be -- to be in love with him the moment he said he was with me? How was I to have an attachment at his service, as soon as it was asked for? His sisters should consider me as well as him. The higher his deserts, the more improper for me ever to have thought of him. And, and -- we think very differently of the nature of women, if they can imagine a woman so very soon capable of returning an affection as this seems to imply.

Sir Thomas offers to break off his daughter Maria's incredibly beneficial engagement to a very rich man. Why? Because he can plainly see she does not love him.

Emma

Mr. Knightley, when he offers to dance with Harriet after she is snubbed by the pompous and mean-spirited Mr. Elton. Even more awesome since she regards this as more exciting and memorable than being rescued from very scary gypsies by Frank Churchill.
Mr. Knightley, again, when he admits his own faults during his proposal to Emma and says he loves her, believing her "faultless in spite of her faults," and that she has borne his rather frequent lectures "as no other woman in England would have."
Emma herself in her epic, chapter-long epiphany near the end of the novel, in which she not only realizes how wrongly she has thought and acted, but also that she is in love with Mr. Knightley. That level of intelligent self analysis by a spoiled child is really impressive - all the more so as she directly decides to do the right thing instead of scheming to supplant her rivals.
- Though not quite as impressive as the climactic epiphany, Emma's post-Box Hill thoughts and actions are also highly awesome.

Persuasion

Anne Elliot, one of the most overlooked and underestimated of the Jane Austen heroines, faces her controlling father and informs him that no, she is not going to visit their cousins the rich and ennobled Dalrymples, she is going to visit her poor friend Mrs. Smith.
Later in the book, Anne informs her love interest that she was in fact right to follow her friend's advice to break up with him eight years ago. He agrees. However, when he admits his fears that he thought her relatives were trying to persuade her into another marriage this time around, she makes it clear that, although a girl's duty to her family may require her not marrying someone, no sense of duty should ever compell a girl to marry someone against her will or better judgement.