Personally I have a mix. I have canned goods which will last "forever", but they say the taste deteriorates after 3 years. Most of which I rotate as I use most things on a regular basis. I have perisable foods though that have to be used right away. I also have some freeze dried foods that will last 5 years or so. I rotate them through camping. Finally I have some MRE's that also are only good for 3-5 years. I think the key is to make sure you rotate. Also if you are stocking a food supply the key is to take your time, unless you're rich. When Mac and Cheese is $.25 then buy a few extras versus when they're $.50. Always buy on sale, and buy what you normally eat.

My $.02 worth