Xbox One is planning on becoming backwards compatible with Xbox 360 games, currently only few games are playable (Banjo Kazooie/Perfect Dark/Mass Effect 1 are a few).. Halo MCC is already on Xbox One and Halo Reach will be added to the backwards compatible soon.. Destiny on Xbox One will allow you to transfer over your Xbox 360. I would choose Xbox One since any achievements you earned on X360 will carry over to Xbox One and you could just buy Taken King and get all the DLCs for free.