I grew up on 2% milk, and it's still my preferred blend, but recent health issues have forced me to switch to skim, which tastes watery by comparison. But it's better than nothing. Whole milk (4%) is good, but tastes a bit too rich to me, I'm sure because I'm used to 2%.
Why is milk so good? I always figured that it's because it's the stuff you could actually live on for the first several weeks of your life, maybe longer. What could possibly be better for you than something produced in a living mammal specifically for the nutrition of a living, growing mammal?
I'll drink a cold glass of milk just 'cause I like it, but for me the amazing thing about milk is how it makes other stuff better. Cookies and milk. Cereal and milk. Cake or pie with milk. Peanut butter and jam sandwiches and milk. And so on...