I'd want to go to a planet with animalistic Wayne Barlowe-esque life forms. I could be wild woodsman, living among the animals, drinking from streams, eating alien fruit, hunting large herbivores with spears, wearing alien animal skins as colthes, the only lifeform on the planet with the intelligence of a human. Oh the thrill, the excitement, the adventure that all that would be! Perhaps I could find a pack hunting carnivorous species (like one of Barlowe's prongheads), find a cub abandoned by its pack for being born an odd color, and domesticate it. It'd be my companion - a misfit among its kind just as I am a misfit on the entire planet, but secretly we both long for the companionship of a member of our own kind. We look around and we see animals with their kin, filling both our hearts with bitterness.