Spain, Germany, France. But I would recommend you rural places, they having unique architecture and design.
I was thinking about Spain too, has nice beaches and very cheap as well.
Spain is a lovely country, but don't forget to take in consideration an other countries.
Tropic places are expensive, I was thinking more europeif you planning, check tropic places, they are very beautiful places to visit. Also depending on your budget.
Scotland has nice places to visit, very lovely castles.