What a hard question. I am so done with bananas after eating them trice a day for 14 months straight, that I still don't eat anything tasting banana over a decade later.
I do not have a sweet tooth, so anything sweet is not getting on my list of 1 fruit for the rest of my life.
I like avocado, blueberries, raspberries,cloud-berries, gooseberries, cucumber, plum, tangerine, clementine,lime, lemon, kiwi,papaya, mango and cacao- the cacao pod is technically a fruit and so is coffee berries, so unless they are in another category I'll go for coffee.
Coffee, blueberry and cloudberry is on the top of my list. They all also make excellent drinks.