I recommend Madrid as well. I still haven't made it to Barcelona but I did visit the Spanish Riviera also known as the Costa del Sol. I stayed in Torremolinos where a lot of English winter and there were a lot of American sailors in the bars as well. Its a short distance to Malaga which was interesting.

Also went West and caught a boat to Tangiers in Morocco for a day trip. It was my first time experiencing culture shock. Tangiers was so different from either America or Europe. I made friends with two Danish soldiers and the three of us explored the Casbah together. It was also the first (and last!) time that I ate a sheep's eyeball! Little kids everywhere were begging for money. I understood perfectly why they spoke to me in English. But when they found out my friends were from Denmark they switched to speaking perfect Danish! These kids knew a smattering of a dozen languages or more.