Northanger Abbey (2007)
Northanger Abbey is a tricky novel to adapt, because it's not quite as timeless as the others. After all, Austen was satirizing the Gothic novels that were so popular during her time. That sense of humor is integral to the story of Catherine Morland — a Gothic-novel-obsessed young woman who believes she has stumbled into a real-life Jane Eyre scenario. The 2007 TV movie is such a delight, because it doesn't simply laugh at Catherine's growing sense of foreboding, it also acknowledges that she's a young woman who has wandered into a strange world of money that's scary with or without dark family secrets attached.
Add in a charming, but never cloying, performance from a young Felicity Jones as Catherine, and it's easy to proclaim this film one of the most underrated Austen adaptations out there.