For me, a lot of it comes down to where you source them - like the ones at the common grocery store are often just nothing, but the same thing fresh from a farmer's market or whatever can be amazing, anyway:

Blueberries, Pomegranates (mostly for degree of difficulty to deal with really), Plain red 'delicious' apples, Grapefruit (I don't dislike them, they are just 'OK'), nectarines (same as previous)