Seconding what they said. The Wide Sargasso Sea is a brilliant re-imagining of Jane Eyre (and, y'know, deals with the stuff I find really problematic about the source text, just like transformative fic).

Maybe Persuasion? It is my all-time favourite Jane Austen (pushing hard to be my all-time favourite novel, ever) - more muted and nuanced than P&P.

And I'm so with the two of you in not getting on with Wuthering Heights.