Which two planets have the most elliptical orbits?

Basicaly, the farther away from the sun the planet is, the more elliptical the orbit is because as a planet moves away from the sun it is losing attraction so it goes further, but eventually when it turns around, it get pulled almost directly at the sun. so it comes very close to the sun but then with all the speed it has gained, it manages to hurtle by with tremendous amount of momentum which is what allows it so get so far away from the sun again and repeat the cycle.

Hope that helps