This one's not just a video game. It's a way of life. In 2044, people get away from the dystopian world by escaping into the Oasis, basically a sprawling massively multiplayer virtual haven that becomes the last frontier for everything: business, pleasure, education, and, of course, gaming.
The Oasis is virtual reality endgame. It's the ultimate immersive experience. You wouldn't just play as a character. You would be the character. Who'd say no to living out any and all of their fantasies? Besides gaming, the Oasis also lets you experience your favorite movies as if you were right there in the scene. And vacation possibilities are limitless. Who cares about going to Hawaii when you could kick back in Gallifrey? Or go to a spa in virtual Paris? You can look exactly how you want to look and do whatever you want to do. All without ever having to leave the comfort of your house.
The whole "never leaving your house" thing is (shockingly) kind of a problem. The main protagonist of Ready Player One slowly discovers how, by becoming so ingrained in society, the Oasis has become a substitute for all experiences. Your virtual life is now your only one. The real world is left to rot away.