Assuming favorable ambient conditions, such as what you'd find in most households these days, what food items will last the longest?

My first guess is vacuum packed dried legumes.

There are a few storage life numbers for various foods at this site. Though I've also heard that similar numbers such as those quoted there are quite conservative, especially where hard grains and dried bean are concerned.

Benjammin, I guarantee you, if I have vacuum packed dried legumes in my stores they would be the very last thing I would eat and therefore by default be the longest lasting.

In all seriousness great question. I think it would have to be a dehydrated type of vegetable, fruit, etc., that has been vacuumed packed.

This begs the next question, how long do you think this item will last undisturbed before opened? 1 decade, 2 decades? Longer?

There could of course be a strong case for great-great-grandmas Christmas fruitcake. I hear some of those last 40-50 years.

Easy. Twinkies. No contest.

He said food items. LOL

Salt and honey.

I've heard many times about,Dates, that were found in the Chambers of Sarcophagus in The Egyptian Pyramids,of which were intact & edible,Though I have met No person,that actually Ate one!

Get me one, we'll find out.

Dried fruit is my crack.

I read some of that article Nicodemus hot-linked. Interesting. I never thought about using TVP as afood storage item. Anyone have any experience with it?

I have a 22 year old tin of anchovy paste, if that helps.

I would guess wheat berries. If you keep them dry and the bugs away they should last longer than any of us will be around. Most of the grains and legumes will last extremely well as long as they stay dry and bug free.

An Army Colonel at his retirement party opened a C-Ration pound cake he has been carrying with him since 1973. The C-Rat was made in 1969.

C-Rat pound cake

No matter what the expected shelf life, I'd have been a little hesitant about eating that,

I read in Nat. Geo. magazine years ago that archaeologists in Egypt found wheat and grains in mummy tombs which was still good, even sprouted. It was several thousand years old.
Salt and honey will never decay or "go bad", unless contaminated by some outside source.

Ditto honey not going "bad" just dehydrating.

Personally, something like rutabaga or asparagus, since I don't like to eat them. In fact, I might starve to death first.