I've only ready Pride and Prejudice and Sense and Sensibility so far but both were excellent. She was clearly a talented writer but for me what makes her really stand out is the dialogue, it's so witty.
"You take delight in vexing me. You have no compassion for my poor nerves." "You mistake me, my dear. I have a high respect for your nerves. They are my old friends. I have heard you mention them with consideration these last twenty years at least."
"You judge very properly," said Mr. Bennet, "and it is happy for you that you possess the talent of flattering with delicacy. May I ask whether these pleasing attentions proceed from the impulse of the moment, or are the result of previous study?"
"Well, well" said he, "do not make yourself unhappy. If you are a good girl for the next ten years, I will take you to a review at the end of them."
It's this type of dialogue that really brings the characters to life. I remember rolling my eyes every time Mr Collins would speak and cringing when Mrs Bennet would open her trap.