All Jane Austen really, but these two are my favorites.
Harsher than Austen, but still oh so good.
Magical fantasy fun times in Regency England.
Julia Qunn is an auto-buy author for me. All of her books are set in Regency England and I adore them all, but this is my favorite.
And as a bonus, here is the WORST Regency set novel I've read:
What is notably missing from this list?
GEORGETTE HEYER Why? I've always wanted to read her books, but am a little scared. I've heard so many great things and I don't want to hate them. Also there are so many and I don't know where to begin. If anyone would like to help me with this I would love to hear your suggestions.