There's no hard and fast "best" of the two. Not at this point in time.
PS4 is a more powerful system and more complex games/those who push the hardware tend to look better on the PS4, better look and higher/more consistant framerate.
XBone has a better, more comfortable controller, though the PS4 one is a lot better than the PS3, where the 360 controller was massively superior.
If all your mates have one or the other, than that should be a consideration.
If you're a particular fan of Halo or Uncharted, or Killzone, or Gears, than that should be a consideration.
EA Access (XBone only) gaks all over that
PS "rental" system.
XBone backwards compatibility coming soon is also a significant net positive.
Both decided to be dicks about allowing previous-
gen controllers and peripherals to work, right down to a ridiculous incompatibility with Bluetooth headsets.
XBone had some serious missteps early on (TV hub focus, always-on DRM, mandatory Kinect) but these have mostly been rectified.
PS4's user-accessible/upgradeable HDD is a point over the XBone's inaccessible HDD.
however
XBone being able to add external HDD for game content is a point over the PS4's inability to do the same.
On balance, the Xbone's expansion system is a little better. Obviously the ability to do both would be the best. Hopefully Sony can add this via a software update and MS can with the next physical revision/slim.
The XBone's UI is horrible. I'm hopeful the upcoming update will improve it. The PS4 system is better, but still not great.
My personal preference of the two is the PS4, just as it was the 360 of the last generation. Both are still good machines. I still own an Xbone and PS3 however.
The
PC obviously has it's good points as well (KBM to start with!), but this thread isn't about that, so
PC Master Race gloating is just being dickish. Also, I'll take Batman on PS4 over
PC.