Well if you want fast paced, but very fun - get Tomb Raider. I actually just got done playing it on PS4. Only downfall is, it's extremely short. Like about 6-8 hours game play for me on level hard. Lots of people said if you've played it on PS3, it's the same game for PS4, just includes all the materials, dlc and booklets which whoopy do...
If you want longer, more involved - go Black Flag. Since I just got the PS4 recently, Black Flag was the first game I played and beat. There is/were lots to do, good amount of gameplay if you do some of the side stuff - and overall pretty fun. If you played the previous AC game prior to Black Flag, and liked the ship parts - you'll love BF then.