Okay, I can't find the actual route I took as I did have to edit it slightly on the fly anyway, but this was my plan:
https://www.google.com/maps/d/edit?mid=zzC6a6zGdH_o.k5qpKT6dKHXI&msa=0
The roads into the Sierra Nevada are massively worth doing, as is the road into Ronda. There's a little squiggly bit too just after that, again that was put in for a reason
I can definitely recommend sticking with the road to Girona once on the N260, it's one of those roads you never really want to end. I know you said that Gib doesn't interest you, but it's a really quaint place to visit if you can find the time. Plus, monkeys!
Worth a divert into Portugal if you've never driven it before, I'm gutted I don't have the exact route to hand as there was a stunning dam just near the border that was epic to drive over.
As you go past Zamora, go east towards Toro. There you'll find the Hotel Valbusenda, which is simply the most amazing place. It has it's own winery on site, the rooms are amazing, but the food is absolutely out of this world. Unless you have another place to stay that you're sure is better, then you MUST stay there.
When you're that far north, the Europas are so close that you probably should take a peek. I didn't get there due to a bout of acrophobia, but I've no doubt they're stunning. The northern coast road isn't as exciting as you'd hope, certainly not after the beauty that is the south.
Tbh though I loved it all, it's my favourite driving country and everyone is so friendly. You'll love every second of it, I still need to go back again myself one day.