Hey oh
Define Ultimate :D
Really, I've made banana bread for many many years. There are dozens and dozens of variations on the theme, but essentially it is quick bread with 1/3 liquid replaced by 2 cups pure of fillintheblanc. As long as the pure has the consistency of mashed bananas it will work.
I have used blends of dates, coconut, pecans, raisins, almonds, dried apricots, and many I've forgotten from the years gone by. I've also had a friends that used banana liquor that was really moist and tasty :D I just don't have a clue how she did it, if it was before or after cooking she added the liquor ;)
HOWEVER, for me, if it is to be banana bread, it needs to be made with bananas that are nice, ripe, nearly black, soft, gooey, squishy, drippy, and then it is banana bread :) No nuts, no raisins, no chocolate chips, nothing to compete with the bananas and the bread of banana bread to be banana bread :D