I second this motion

While it scored great, a gem such as The Talos Principle should have had a bigger critical acclaim, and while sales were good, it should have made massive numbers. Everyone should play that absolute masterpiece, I tell you!

Runner-up would be The Evil Within. Incredibly game, long without overstaying its welcome, awesome atmosphere and entertaining gameplay with good difficult spikes here and there. The story has some very weak moments, but overall everything else is great. I've always felt this gem is incredibly underappreciated.

Lego city!

I love the world, the cars and the different mechanic you could do.

Tokyo mirage sessions. It probably has my favorite battle system out of any jrpg and the character progression/customization was really good too

Forza Horizon 3

Until Dawn

I'm going to take underrated as under appreciated I.e. not enough people supporting the game via purchase. 

1) Tearaway Unfolded 

2) Gravity Rush Remaster 

3) Until Dawn 

4) Alienation 

5) Driver Club 

Fatal Frame: Maiden of Black Water

For all its imperfections, it delivered in spades where it counts; an eerie atmosphere and bone-chilling scares.

Color Splash, because it is an excellent game, but was doomed to be hated since it's reveal, and that makes me sad.

Tokyo Mirage Sessions #FE, The Wonderful 101 and Fantasy Life for me.