As proven with my intense love for the zombie genre, Dead Rising, and the Master Chief character, no game will make me get an Xbox One. That said:
1. Price drop. Even with the Kinect 2 it shouldn't be more than $450. I got my PS4 and the Camera for less than the cost of the One.
2. Drop paid for, timed (or otherwise) exclusivity. Meaning make first party exclusives, quit paying for third parties.
3. Drop required Live for services such as Netflix, Hulu, web browsing, etc. That is utter nonsense and they know it.
3.5 Make all general online interactions free, ala PlayStation Plus. Makes no sense at this point in the industry to keep Live the way it is structured.
4. Bring us ALL the features promised when it was first announced WITHOUT the bull spit policies first intended.
5. Change that damned controller. Those shoulder buttons are way too close to the triggers.
6. Start giving a damn about the customer. Sony does it with free online services, phenomenal rewards for Plus, and by actually listening to fan feedback. Nintendo does it by a completely free online infrastructure, producing high quality first party titles, and giving us fun over flash.
7. Put the focus back on gaming. Drop all this nonsense "all-in-one" fluff.