No. 1: They Are Simply Great Games

Set aside all other aspects of Pokemon. Set aside the adorable critters, lovable characters, collectible cards, and rap song. You're left with the foundation of the whole Pokemon franchise. The games. They found one of the best RPG formula's around and they've stuck with it, riding it all the way to outrageous success. You move through a lovingly detailed world collecting and battling little monsters in an effort to be the greatest there ever was. The random encounters kept us always guessing and on the hunt for more rare and powerful Pokemon. We studied our Pokedex for clues to defeat new and unknown foes. The battle system was simple, fast, and strategic. What more could you want? Sure, they've switched up the Pokemon and the locations a bit, but the soul of the games remain the same and that is why we still love Pokemon.