The primary purpose of any game, regardless of it's use should always be to have fun. Gamification is a whole thing that would continue to move forward but even then any good game has to be fun before it's anything else or it doesn't work. Personally, I think that seeing people enjoying themselves is generally a pretty entertaining experience all all by itself. Seeing someone do something that they really enjoy, even if I don't enjoy what they're doing just tends to bring a smile to my face. It's in this spirit, that I really enjoy watching Clueless Gamer by Conan O'Brien.
Conan O'Brien will openly admit that he isn't a gamer in any sense of the word. Yet it's because of that fact, that you can see him experience games almost in a way that gamers might not otherwise see it because he doesn't take for granted some of the tropes that we commonly see in games. These can more or less be just called extended ads for the games involved but frankly I think they're too much fun to pass up. Here are a few select episodes to check out. I would highly encourage you to check out the rest though should you be so inclined.
https://www.youtube.com/watch?v=xCe8-1dbXZc
https://www.youtube.com/watch?v=SfjLRuE1CLw
https://www.youtube.com/watch?v=_1hkSUGgPC8