Nicholas Sparks is definitely awesome.
Have you tried Wuthering Heights? It's a really twisted love story, but it's pretty awesome nonetheless. Another messed-up love story is Dickens' Great Expectations.
Also, Lurlene McDaniel, I don't remember if her books are love stories, but they're really good too. She's more of a young adult writer, I'm not sure what age-type you're looking for...😳
I shall keep replying everytime I remember another one! :D
Love,
Bhav (: