Coke Tales in Milan is a beautiful bar located in the Porta Venezia area. It's very small, and has only a few tables inside and a couple outside.
The interior is beautifully decorated in Liberty style, perfectly integrating with the Liberty vibe of the area. If you don't know the Liberty style is the Italian equivalent of the French Art Nouveau.
I highly recommend booking, as it'll be hard to get a table otherwise. This place is perfect for an after-dinner drink.