GG

Acronym that means good game.

It is often used under videogame contexts: however, as videogames become more popular, this expression has become more widely used in daily life.
A major use is under the situation when something is over and it was worth the try but the outcome was not exactly the expected one, specially way less than expected with a big plot twist.

1.
Girl: After planning all weeke we can finally celebrate your birthday.

Chad guy: I'm going out with my friends.

Girl: GG

2.

Me: I studied days for this final, I'll def do well.

Professor: You failed.

Me: GG