Here's why:

* Great Red Spot: This is a massive, persistent storm that has been raging on Jupiter for centuries. It's so large that Earth could fit inside it several times over. The spot's color, size, and shape have varied over time, but it remains a prominent and easily recognizable feature.

* Rings: While Jupiter does have rings, they are much fainter and less prominent than Saturn's rings. They aren't as instantly recognizable as the Great Red Spot.

* Dark: Jupiter itself is a gas giant with a very faint, dark appearance. While the Great Red Spot stands out, its darkness is not a defining characteristic of the planet.

* Elongated Orbit: Jupiter's orbit is slightly elliptical, but not significantly elongated compared to other planets in the solar system. This is not a particularly distinctive feature.

Therefore, the Great Red Spot is the most distinctive feature of Jupiter due to its unique appearance, longevity, and size.