My son still gets some breast milk, and the only other milk he likes is Horizon chocolate milk.

Given the nutritional profile of milk, it's actually more like a food. I always treated it as a snack if it was between meals. Kids do need the good fat and nutritionally sound calories, so milk is a better option than say crackers and juice.

That being said, too much milk can cause problems. If the child is drinking milk and gets full and then can't eat enough fiber the child can become constipated. Milk is a low-fiber food and we know how important fiber is for us.

The other problem with drinking too much milk is that then kids may not have enough room to eat iron-rich foods. And milk can also inhibit iron absorption. This leads to iron-deficiencies which as been medically linked to behavioral issues and learning delays.

Toddlers should have no more than 3 servings (24oz) a day. Most kids won't drink 1 serving (8oz) in one sitting, so just keep track throughout the day.

My kids have never been big milk drinkers. They will drink chocolate milk periodically and that is about it.  I see families buying several gallons of milk a week, and we go through a gallon and a half every 2 weeks. 

My kids (4 & 2) drink whole milk. I don't regulate it. They only get milk or water to drink. Milk is offered at meals, water in between.  Between the two of them, they go through about 6 litres (canadian) per week. They do get milk between meals if they request it, and some meals they choose water.
My 2 year old, I only give him milk in a cup with no lid at the table. I don't do sippy cups with anything other than water as I have seen too many other people find them with mold or even worse, find one that used to have milk in it that disappeared weeks ago and is rotten under a couch.
my youngest still drinks a bottle at nap & bed time and I switched it to water a while back. He still gets the comfort of sucking but it is just water which I figure is good to rehydrate him as he is often busy playing during the day that he doesn't stop often enough to drink especially on nice weather days.

We drink milk at meal times and water the rest of the day. (Sweet tea is loved, but is only given as a treat!)

My son is a huge milk drinker and I've had to limit the amount of cups he drinks so he will not be too full to eat. I celebrate when my daughter has had 2 cups in a day. =)