PS4. I own an XBone, and it's really only because my friends suck, and won't switch to PS4.
The Xbox One interface is shit. Complete, and utter Windows 8 shit. You're not notified when someone comes online, checking the achievement details of an achievement you just unlocked is a huge step back from the basic implementation on the 360, no auto sign in to your account unless Kinect recognizes your face, stupid assed Windows Phone infinite back button setup, where if you're on the dashboard and you hit the back button (B), then you go back to the previous app/game/whateverthefuck you were in, even if the last time you were in that app was the last time you used the xbox.
On the flip side, I played a PS4 for a bit at a co-workers place, and the interface was simple. Granted I didn't poke around pretty much at all, but it seemed a lot less intricate (in a good way) than the XBone. I couldn't play FPS games on a PS3 because of how the shoulder buttons worked, but that was remedied on the PS4, and while I still like the Xbox controller better, the PS4 controller isn't that bad at all once you're a few minutes in.
I'm getting a PS4 in the next couple of months, but with the launch titles for both consoles being what they are, I got the xbox first since like I said, my friends are assholes.
If I decided to sleep with all my friends girlfriends, and they ended up hating me for it, I'd be on PS4 almost exclusively. (Still WTB: Titanfall).