If you’re in Europe then you have a fair bit of choice. Nintendo are offering the games in steel book editions with a figure of either Groudon or Kyogre depending on the game you pick via their online store. Video game retailer GAME are also offering the games in steel book edition, but they aren’t giving out the figures that Nintendo are. If you happen to be buying with online retailer ShopTo then you’ll be getting a keychain featuring Torchic.
If you’re in North America then you also have quite a fair bit of choice as if you order from GameStop you’ll get a bonus poster. If you happen to order a copy of both of the games from Toys R US you’ll be able to get a Mega Charizard X or a Mega Charizard Y plush toy.
If you happen to be in Japan then you’ll get a bonus figure of Groudon or Kyogre with the games (different figures from Europe as well). If you buy both copies of the game then you’ll also be getting an artbook.