It really depends on your goals.
If you want to gain/bulk, then I would say milk is good source of whey and casein (it's a 20:80 ratio) and you could eat cottage cheese and drink milk w/o concerns.
I am currently on a cut, so I cut all dairy products.
Chocolate milk has loads of sugar, plus whey and casein protein. Keep in mind that those football players workout for longer than most of the normal people, so they need to replenish their glycogen quick. Therefore I would say chocolate milk might not be the ideal post workout drink for the average joe.