My GOTY so far is Dying Light.
But it is one of the only two 2015 games that I've played (not counting MLB The Show), and I didn't like Bloodborne at all, deleted it after about 2-3 hours of respawning...
For the rest of the year, the game that interests me the most is Just Cause 3, and am looking forward to playing Until Dawn, although I don't expect much quality, but simple pure fun.