I was close to picking Fire Emblem except for the whole impending destruction thing every time, and Kirby or Mario would be good except that in Mario you're either a redundant mushroom-man or stomping fodder, and in Kirby you're either digested or about to be. Although I would be partial to being Metaknight...
But no, I picked Pokemon because I would be able to apply logic and succeed immensely. For example, if picking up a curiously obvious item, I would look at it from a 3/4 view first to discern if it is an item or a disguised mushroom/failed pokeball. I would also be able to get rid of trees with fire attacks instead of cut, and teach my Pokemon how to use a Revive so it can use it automatically. And unlike every other character in the game, I would know about the effectiveness mechanics. Oh and if a criminal organisation showed up I would CALL THE F***ING POLICE. God knows they make enough public speeches, there are any number of opportunities to straight out arrest the leader.