Personally I believe prisoners are entitled to the minimum in the way of sustenance, a place to exercise (no weights), medical treatment if they become ill or injured, a place out of the elements to sleep and that is it.
Coffee, TV, books, music and all the other things enjoyed by law abiding citizens should be denied. The difference between law abiding and law breaking should be brought home as plainly and painfully as is possible.
I think the post right after yours nailed it, talking about those things be what prison riots are all about. They have gotten the idea that "3 hots and a cot" includes TV, cable, internet, law library, imported egyptian towels for shower time, etc.