Adam and Eve (Biblical Mythology) once ate the Forbidden Fruits which granted the knowledge of good and evil, but with the price of being cursed by the concept of sin in disobeying God and are forever curse with the knowledge of sin.
The Qliphoth Fruit (Devil May Cry 5) imbues any demon that consumes it with sovereign power to rule over all...
...granting Mundus enough power to slay the previous ruler of the Demon World and take the throne for himself...
Turles (Dragon Ball Z: The Tree of Might) holding a Fruit of the Gods, which was spawned by the Tree of Might when it absorbed an entire planet's natural energy, granting its eater massive increase in power.
Spawn (Image Comics) ascended into a being equal to God and Satan after eating the Forbidden Fruit from the Garden of Eden.
Locacaca Fruits (JoJo's Bizarre Adventure Part VIII: JoJolion)
Immature Lockseeds (up) (Kamen Rider Gaim) turns their consumers into Inves at the same time granting them powers. One must wear a Sengoku Driver which ripens them (down) to consume it's power safely.
Produced by Divine Tree, the Chakra Fruit (Naruto) grants the consumer incredible reserves of chakra.
A Rubber Human, Monkey D. Luffy (One Piece) become a "superhuman" or Paramecia class Devil Fruit user after accidentally eating the Gum-Gum Fruit/Gomu Gomu no Mi as a kid.
A Fire Human, Portgas D. Ace (One Piece) became a "elemental" or Logia class Devil Fruit user after eating the Flame-Flame Fruit/Mera Mera no Mi.
A Leopard Human, Rob Lucci (One Piece) became a "animalistic" or Zoan class Devil Fruit user after eating the Cat-Cat Fruit/Neko Neko no Mi: Model Leopard.