Having been born and raised on peanut-butter and jelly sandwiches, I have come to the conclusion that the infamous PB&J is by far the most ideal and tasty sandwich of all time.
By consuming no less than fifteen thousand of them (assuming I have had at least one a day since my second birthday or thereabouts), this can be proven beyond a resaonable doubt. In fact, it would easily be the 'ideal sandwich' if and only if it did not make one's hands so sticky afterwards.
This is due to the inherent gooey characteristics of oozing jelly combined with a voracious biting style and an overly sloppy chewing technique.