Generally, if you enjoy a good coffee drink, you'll get the best flavor from whole milk. Many coffee gourmands won't even consider using anything less than whole milk in their beverages. More milk fat equals more flavor -- it's as simple as that. Interestingly, though, more milk fat also means decreased foam. Foam (or frothed milk) is what you see on the top layer of a cappuccino. If you like a foam mustache with your first sip of cappuccino, then ask for skim milk, not whole.