Kerbal Space Program - the only thing that can make you understand orbital mechanics and how space flight works. Highly recommended for who enjoys this kind of stuff, you could esily spend 1k hours on it.

Left 4 Dead 2 - a gem, hands down the funniest game to play with friends.

Portal 2 - Valve's masterpiece, gorgeous story and concept.

Dark Souls - it's simply a great game.

Factorio - highly addictive and fun. I've currently built 3 or 4 factories up to rockets and it still doesn't get old.

my favorite game is probably all the smash bros games.

games* what.