I still have a soft spot for MREs - Meals Ready to Eat, or as we were told at the time, the rather less PC Meals Rejected by Ethiopians. Other than the chilli cheese dip, they were largely awful, but you could have some real fun making 'MRE bombs' which was a childish if not amusing way of whiling away several months.
Strangely enough though, I do like the biscuits brown in our own rat packs and I have absolutely no idea why.