Bananas. 30 minutes later it's "hello fibre and potassium, time to visit the loo!" But seriously, there are so many great fruits.
Some from me: Blackberries are my hands-down favourite (and available everywhere in the wild in the UK autumn), raspberries, apples (so many varieties), navel oranges, mandarins, dragon fruit, watermelon, pears, rockmelon/cantaloupe, soft peaches (rare; most need a hammer and chisel), plums, damsons (in jam), and grapes.
Pink lady apples, Sugar Bee apples a close second. Both crisp, but SB being sweeter and a bit crunchier. Pink lady gets me with the sour though, so good.
Cara cara oranges for sure. Shower orange of choice. So juicy!!
Normal red cherries in the summer. None of that rainier stuff.
For just sitting there eating peanut butter on an apple, a honeycrisp. I used to go for Galas because they were cheap, but lately I decided $1 more per pound of apples is better than occasionally eating a dozen donuts when I want something sweet. Overall, just better to spend more money on healthier food than to absolutely optimize my grocery budget then binge on junk food when the optimization freaks me out.
We get these fresh here, and wow I agree, these are so sweet and flavorful. Even if they don't look as ripe as the other ones they taste better, you can smell them when you approach the display.
Ojai pixie tangerines are amazing. Sweet, juicy, easy to peel, not too much pith, and a wonderful flavor. Every year when they're in season, I go nuts eating them.