I've been recently been thinking about Arkane Studio's Prey which is a immersive sim, with a pretty good rogue like dlc, that probably has one of the strongest hooks of any game I've played. If you liked Halflife, System Shock, or Deus Ex it's definitely worth a play.
Are there any titles that might not have been commercially successful that you feel everyone should give a shot?
Titanfall 2
Bought the game at Dollarama in Canada for $4 a few years ago. Still haven't played it.
The campaign has some absolutely wild parts of it. It's worth playing through that if nothing else