You're missing a shitton of exclusives. Sunset Overdrive and Dead Rising 3 on the XBox side are great, with Until Dawn, Infamous and Street Fighter in the PS side.
They're both very similar this time around, although PS4 gets slightly better versions of games as it has more power. Things like MGS and Battlefront will run at a higher resolution on PS4.
I'd just take a look at this list and get the system that has more you want to play:
https://en.m.wikipedia.org/wiki/List...th_generation)
Both XBox Live and PlayStation Plus give you 2 free games per month for either system.