for me the contenders are..
The Withcher 3 (press fav)
Bloodborne (press favour and good game)
Fallout 4 (the name counts a lot in this case)
Batman Arkham Night (everyone agree it is a great game)
Pillars of Eternity (Baldur's gate flava)
Splatoon (with all the free extra content it becomne a very great and fresh game)
Xenoblade Chronicles X (Personal choice, love Monolith Soft and Xenoblade)
Legacy of the Void (great final for a great trilogy)
Halo 5 (will be in the conversation but won't win the prize)
Super Mario Maker ( Great tribute to a great franchise and its fans)
I made a top 10 contenders... maybe I'm missing some indie games... I don't remember any indie game as great as Journey was
PD I forget SW Battlefront !! With the big momentum SW will have this ywae and how looks thw game it will be in the conversation for sure
PD2: what the fuck!! I also forgot MGS5 !!
Well if I'm not forgetting any game (maybe an indie) those 12 are the contenders or will be in the conversation.