Last summer I travelled to Milan and absolutely fell in love.
It's a beautiful city, rich in culture and even richer in amazing ice cream.
If you enjoy walking, architecture, shopping and eating, I'd highly recommend visiting Milan. 3-4 days would be the perfect amount of time to cover majority of the main sites, it'll keep you very busy but allow enough time to really enjoy it.
Going back through the pictures is causing me a serious case of wanderlust!
Milan, you have well and truly stolen my heart!