Jen, "Gone Girl" was terrific - I read it in 24 hours.
Have you read the Outlander series by Diana Gabaldon? There are currently 7 books in the series, with the 8th due out next year. You've asked for historical fiction and romance that are well-written - this series fits your criteria. (In case you don't know about this series, the books in order are: 1) Outlander, 2) Dragonfly in Amber, 3) Voyager, 4) Drums of Autumn, 5) The Fiery Cross, 6) A Breath of Snow and Ashes and 7) An Echo in the Bone.) These are big, thick books to get lost in; and depending on how fast you read, you might still be reading the series next summer! I have all of them in trade size, some in hardback, and now I have them on my kindle, plus all of them in unabridged audiobooks - can you tell I'm a fan?