Splatoon 2

I still have to buy, besides many others in my wishlist, The Witcher 3, Project CARS, Assetto Corsa and rFactor 2, so one of them.

Destiny 2, only if it gets praise from credible reviewers. If not, then Horizon Zero Dawn.

This thread would be a much better idea after E3. Anyway, I'm not familiar with all the releases with year, so the new Assassin's Creed comes to mind as one of the few good options. That or Crash, but I think I can spend more time with AC.

Now if we're talking about previously released games I don't own yet, there's probably going to be a ton of other good options too. Ultimately, I don't have any need to get a single game in years though, considering how many untouched great games there are still in my backlog.

Ask me after E3, but for now GT Sport.

Splatoon 2

Either Super Mario Odyssey or Xenoblade Chronicles 2

I'm still skeptical about Xenoblade coming out this year, but that would win just for sheer hours debate. I would get more hours into that game that Mario. A good RPG is always best bet, unless there is some awesome MMO, but nothing I know of.

Since both come out in holiday season at best, not a long wait to get the other. Plus I assume I can still play the Zelda DLC and that doesn't count since I already have the game.

Wait, can I still play other games I own?? Because if I can then the 1 game doesnt matter, my backlog is insane and I never really plan on playing most of them now :P
So Splatoon 2 if I cant play games already owned because its out in July meaning Im not waiting forever and it has massive replayability. Otherwise its Super Mario Odyssey, my backlog can get me through until then easy. Theres a couple cool games releasing this year but I cant see anything that comes close to a new 3D Mario.

Kingdom Hearts 1.5+2.5, because it's actually four games and I'm a cheater ;D

Mario Odyssey