in casual? I've been enjoying Bello a ton, it feels really powerfull and fast, it has been super fun. For cEDH... not sure, there have been a lot of commanders that are almost viable, but it seems like nothing quite gets there. Stella Lee might be a contender...

If you are refering to the pack "wheel" then no, once you pick one it's already determined what you'll get. If you are refering to the Charizard, Mewtwo or Pikachu packs then yes, each have some unique cards and some that are the same