Haha that is the Beauty of Generation 6 Lemon. Pokemon X and Y introduced the most amount of Pokemon in a single game from previous generations. You can nearly complete the Pokedex just by catching and trading Pokemon in that game without having to trade over from your old ones. So you really can guess any pokemon except for the starters I mentioned. I will also give out another hint so that people will be more likely to guess!
My Favorite Pokemon is NOT a Legendary in the Games or any incarnation of Pokemon. It's only a Legendary in my heart but that doesn't count since it's a regular pokemon.