Don't know how to track stuff for PS4 but the top 3 should be:
1. Diablo 3 UEE - Oh how I wish PS4 would get new content. Played until there were basically no more items to get. Some of the most fun I've ever had in split screen.
2. PvZ: Garden Warfare - Just a ton of fun to play casually, preferably taking turns with my wife. I'd play Zombie and she would take over for Flower rounds.
3. Bloodborne - Beat twice including chalices. Has to amount to quite a few hours.
Also played a lot, possibly more than these: Call of Duty: Ghosts, Mario Kart 8 and Smash WiiU.