You've seen the movie, but have you read the book? Margaret Mitchell's Gone with the Wind is an enjoyable Pulitzer Prize-winning novel. Yes, I'd seen the movie multiple times, but I decided to try the book, and I'm glad I did. Given how some movies are quite different from the books on which they are supposed to be based, I was surprised how well the classic movie followed the book. Even many of the conversations seemed to be quoted word-for-word! Having said that, even if you've seen the movie, the book will still give you new things to appreciate. You'll learn more of Scarlett's family's backstory as well as meet characters who weren't in the movie.
Of all the new things that I encountered in the book, though, what I probably liked the best was knowing more of what Scarlett was thinking and what motivated her to do what she did. From watching the movie, I think I had misunderstood some of her feelings and motivations. Having a better understanding of them probably made me like her character better and, perhaps, made her into more of a sympathetic character than I had previously considered her to be. I also really enjoyed Rhett's character and, after finishing the book, probably sympathized more with him than I already did. In the end, I'm so glad I've now experienced the book instead of just the movie. I encourage you to do the same!