PS4 exclusives I have played...
Killzone Shadowfall
Knack
Infamous SS
The Last of Us Remastered
Final Fantasy XIV
Little Big Planet 3
Guilty Gear Xrd
The Order 1886
X1 exclusives I have played...
Titanfall
Sunset Overdrive
Halo MMC
D4
PS4 Exclusives I have not played...
Driveclub
Natural Doctrine (but will soon as I have it here lol)
MLB The Show 2014
X1 games not played...
Forza 5
Forza Horizon 2
Dead Rising 3
Ryse
Upcoming PS4
MLB The Show 2015
Bloodborne
Uncharted 4
Until Dawn
WiLD
No Mans Sky (timed)
Disgea 5
Dragon Quest Heros (confirmed coming to west)
Street Fighter V
Ratchet Reboot
Upcoming X1 Exclusives...
Ori and the Blind Forest
Forza 6
Fable Legends
Quantum Break
Halo 5
Gears of War (way off)
Rise of the Tomb Raider (timed)
Scalebound
Crackdown 3
Phantom Dust
For me, the PS4 has been blowing the X1 out of the water in terms of quality and quantity, but not so much that personal taste isn't a factor. Throw in best multiplat experience and the PS4 wins it by a landslide.
As for upcoming games, both have a decent line up. I would be lying if I said I wasnt looking forward to X1 exclusives. At the end of the day however we get consoles for the games, and the PS4 will edge it out here as well with more to offer and a greater variety of styles.
Just my 2 cents on the subject.