I really like Northanger Abbey - it's one of my favourite Jane Austen books - I think because I love the comments on books and reading, and the play on the Gothic. (This was definitely helped by the fact that I first read the book as part of a subject on the Victorian Gothic, so I had a real knowledge of the genre that Austen was playing with.) I also really like the characters. Henry is possibly my favourite Austen guy, because he reads, he's a decent person, and has a great sense of the absurd. I also like Catherine, because despite being a bit ditzy, she's quite a good heroine. (The comments about her being an unlikely heroine are fun, too!)
I'll be going to my library next week so I can then borrow it out. Just checked my library's catalogue to see how popular it is and there are several listings for the book. Which one do I want?
It doesn't really matter - it's just different publishers republishing the same book, because it's out of copyright. :) I'd say maybe go with the Penguin Classics one, because I think it has the original ending as a bonus chapter, and it's interesting to see how it was written originally. (Well, I found it interesting, anyway. :P)