1) Exclusives. Mainly, Titanfall and Halo.
2) Its the console all my friends have. To many this sounds silly, but if it weren't for my 360 I would barely interact with most of my friends and brother. This is a huge deal to me.
3) I love all the non-gaming functions. Exclusive TV programs, Skype, TV pass through, voice control, NFL integration, Xbox Fitness and all the other extras will be completely used by me. I don't really use my computer at home, so 99% of my entertainment comes from my console. More entertainment on my console means more entertainment for me.
4) Snap is huge for me. My GF lives in the US and I live in Canada, so now I can skype her in without ever stopping my Titanfall session. I like that I can snap in youtube, internet, fantasy updates, live tv. It is right up my alley.
I am not a graphics whore. I am the type of person that is still impressed by the graphics I get on my current gen console, so going from 512MB to 8GB and having a boost in processor should be a good enough jump for me. I think it is funny that almost the entire next-gen narrative has devolved into 720-1080P and GPU.
In a year's time when games are being reviewed, GPU will be a borderline after thought. TLoU did not get such high scores because of the power of the PS3. If the same game was released on the 360 it would have scored just as well. Both consoles will have exclusives I want to play, but I can only afford one (based on finances and time). So I choose the XB1.