I prefer a mug, cups just don't seem to hold enough. I don't like styrofoam cups at all (try leaving a black coffee in one for a bit - it leaks through, which means that it is dissolving something into the drink). Paper cups for coffee work fin, though I have to say if you get macchiato (or even espresso and cappuccino sometimes), in Italy it is in a glass. Since it tastes so good there I have to think that glass must be best.
