Might I suggest our handy dandy Xbox One Master Thread
Download the Xbox app onto your phone. You can control your system through your smartphone, which is actually really helpful for watching media. On that note, if a PS4 is your primary media player, I'd strongly advise to switch over to Xbox. They have a lot more apps and the streaming quality is just better overall in my experience. The UI is better on PS4, but that's a small price to pay for the picture clarity.
Other than that, there's not a whole lot on the accessories front that I'd recommend. A lot of people are really into the Elite Controller, but I never found the need to pony up the $150 for it, so I can't speak on that myself.
Xbox Live is pretty much PlayStation Plus in every way. The major exception is that the 360 games you get every month are backwards compatible and can be played on Xbox One.
As for exclusives, people have already mentioned them, but Sunset Overdrive and Ori and the Blind Forest are the two that speak out to me immediately.