Jeez, this is hard.
1. Pikmin 3: nothing else like it. Never gets old.
2. Super Mario 3D World: Platforming Nirvana.
3. Bayonetta 2: Action bliss. Just a joy to play.
4. Rise of the Tomb Raider: sentimental favorite
5. Sunset Overdrive: Open world rollercoaster ride
(6. would probably be Until Dawn. My favorite "choose your fate" style game.)