The main thing to look for when buying cider from a grocery store is that it has NO preservatives in the juice. If it says Pasteurized on the label it's fine. NO to preservatives, YES to pasteurization! To tell if the juice has preservatives in it look on the label for sodium benzoate, potassium sulfate etc. If it says ascorbic acid, you don't have to be concerned because it's just vitamin C and it won't put the hurt on your wonderful cider! Also if it says shake well before using, you might have just picked up a good cider! If there is a juice that is cloudier than the other I would go for that one. Also it seems like there's much confusion choosing between a cider and a juice.
1. Musselman's Apple Cider - Walmart / HYVEE (my personal favorite, they have juice and cider, get the cider cloudy version
2. Motts – Walmart, Costco, Sam's, Kroger
4. Whole Foods organic apple juice in 1 gallon glass jugs – (Buy the right size rubber stopper and you can use this glass jug instead of having to purchase a carboy!) Whole foods organic apple juice works great in the one gallon glass jugs, you will need a #6 size stopper and add 1/4 can of frozen juice consentrate to it. Bam that easy!
(*Remember for all juices, still read the label closely to make sure it doesn't contain preservatives)