It's funny you made this thread, because I read that page on PA and immediately went to this website to make this exact post as my first post at The Escapist because I thought I finally had something worthy of discussion here. Oh well, lol.
It's true that everybody plays games for slightly different reasons, though I think there's some common threads that unite us. The community, for example, keeps a lot of people playing, especially with MMORPGs (though I think all online games have this aspect to a certain degree). I have dedicated the vast majority of my gaming time to the Unreal Tournament series, and a lot of that attachment has to do with the people I'm used to playing with. Let me back up and try to answer the question more coherently.
When I first started gaming, what got me interested was simply the excitement and action - the challenge of the game mechanics and the desire to see the hilarious/impossible stuff that could happen in a game world.
Now that I've been playing longer and become more accustomed to the whole experience, there are two main factors: The aforementioned community aspect, and something more important, the only thing that can keep me interested in any activity for any length of time: personal improvement. UT has a gigantic learning curve and there are amazingly good people who play it, so it provides an almost endless challenge. Take this within a community that I enjoy being a part of (for the most part heh) and you have the main components that have held my interest in UT over a long period of time.
I still play singleplayer games once in awhile, and the only thing that really matters to me in an SP game is a story. I read a LOT, and I think games have a huge untapped potential as a medium to develop characters and communicate a story. The singleplayer games I select/enjoy are therefore the ones that have strong components of narrative and character development (I love Bioware!). I enjoy seeing the art and concepts presented in a game too, but that alone isn't enough to capture my interest.
So I guess I have a variety of reasons. And the base reason I game at all, of course, is that I have nothing better to do in my free time.
