Whole milk, usually. I can't stand the taste of skim, and 1% just seems a bit... off.
I have been known to accept 2% in times where milk is required but whole milk isn't available. In those situations, it works beautifully. But at home, when I randomly pour myself a glass of milk to have with my sandwich, whole is the only option.
Flavoured milks and non-dairy alternatives aren't considered as "milk", in my mind. They're a different category of drink altogether (yes, even though chocolate milk is still technically milk. I know.)