I'd recommend Seville as a really top city and one that people might not typically think of. I've been a couple of times and I'd put it right up there - beautiful city, huge cathedral, great food and drink, loads of history, 2 decent football sides in Sevilla + Betis and plenty of stunning women.
In summer 2011 I got a flight there and back inc all taxes etc for £20.00 (never had such a cheap return flight in my life) from East Midlands on Ryanair. Give it a shot.