When I was in high school, I discovered romantic fiction - and the popular romantic fiction of the day was by Victoria Holt, Phyllis A. Whitney, Dorothy Eden - and Mary Stewart.
Victoria Holt was my favorite at the time - she wrote many of them; so did Phyllis Whitney. But I think Mary Stewart was really the best. I read a few, not all. She had a gift for description which I don't believe many could improve on - in those days I don't think I was very observant, but I noticed that you could read pages of her descriptions of scenery, and not be bored by it.
Working in a library, her books lately caught my eye for some reason, so I've recently read 3 of them, and the latest was my favorite, Nine Coaches Waiting.
I couldn't put it down, and it's not as if I'd forgotten the story! It still seemed as romantic and suspenseful as it was to me 35+ years ago.
If you're looking for something different, try some Mary Stewart. I think you'll be pleasantly surprised.