I love them all but here's my attempt at a ranking.
- •JupiterBecause it convinced us things don't go around the earth.
- •VenusBecause it's phases taught us more about the structure of the universe.
- •SaturnBecause it marked the extent man's knowledge of the solar system for a hundred thousand years. And it is as beautiful in the sky as it is up close.
- •PlutoBecause I've been waiting anxiously for pictures of Pluto since I was 12 years old and we're getting them THIS SUMMER. This is the current state of the art but they're about to get way way better.
- •MercuryBecause it is an elusive and beautiful naked eye planet.
- •MarsBecause it is the only planet populated entirely by robots and could conceivably be our second home.
- •EarthBecause it is "the aggregate of our joy and suffering" and I think unbiasedly the most beautiful and dynamic object in the solar system.
- •UranusBecause I saw it from our rooftop through the telescope, pale and blue, with Sophia and it was our greatest finding achievement.
- •NeptuneBecause it was the last planet visited by Voyager 2 and the first I remember seeing covered live on the news.