This review of Portal 2 is pretty great. You should read it.
The money quote, as the kids say these days:
Playing Portal 2 made me feel good about myself, and good about the people who designed it. What’s more, I couldn’t shake the sense that the designers felt similarly about me, about the players for whom they designed the game. It’s odd that a videogame should earn special recognition just for respecting its players, but Portal 2 does exactly that.