I finished half of Storm of Swords.
There is a very brief moment of sexual tension in Jaime's thoughts over Brienne that didn't make it to the show.
Also the drama with Stannis and the Red Woman, and the prophecy comes across as being inspired by Shakespeare's MacBeth without plagiarism. In Macbeth, the witches are ugly, and are the 'other', while in GOT the beautiful Melissandre is Stannis' advisor. She is a sexy sorceress instead of a crooked nose witch.
The rigidity and honor of Stannis is excessive, dangerous even (he is kind of like a less charming Ned Stark) and his enthrallment with Melissandre is a rather interesting juxtaposition. However it hasn't been explored enough in the show and is still mysterious in the books so far.
Like Macbeth, Stannis chases a prophecy based on magic.
I'm starting to understand why book reads and superfans were so disappointed with season 5-8. These characters were building up to something bigger than what we got in the show.