Well, anything without MSG <img src="/images/graemlins/wink.gif" alt="" />.
I pack
Datrex food bars in my bug out bags. They taste good (natural coconut flavor), last 5 years, and are non-thirst provoking. Within each 2400 or 3600 cal bars, they are subpackaged individually into 200 calories chunks wrapped in plastic, making it easier to ration out in an emergency.