Sarajevo- I have been in lot of places, but for me its not even close. Sarajevo is the real bridge between west and east, city with a huge history. Smaller than other big European cities, but still with so many places to visit. You will meet the most friendly people in your life on "Baščaršija", you will eat the best food, traditional Bosnian food that is still laughable cheap. I would highly recommend you to visit it whenever you get a chance.
Second one would probably be Milano, because its hometown of my favourite soccer team ACM. Im often there, because its not too far away from my living place. Big city, with great architecture, with lot to offer in every aspect.