The False Fiancee (Signet Regency Romance) - Emma Lange 3+ - I remember thinking this one was so romantic and would make a great movie back when I first read it in high school. It was one of my first traditional Regencies. :) Be forewarned, though, that it's got a mistress element in it since the duke doesn't think Catherine is up to snuff for marriage for 98% of the book.