I have this little tradition: whenever I get a week or so of free time, I play through my favorite video game of all time: Star Wars: Knights of the Old Republic II – The Sith Lords. It is my favorite game because it is one of the very few video games that not only entertains, but also addresses deep philosophical questions with complex characters and well-written, intelligent dialogue.
For example, in the beginning you are trapped on an asteroid mining station that’s being sabotaged. You can just fight your way out, of course; but if you take your time and pay attention, you can gather up lots of clues that allow you to unravel who is sabotaging it and how and why. It’s a great feeling when you piece it all together, because you feel like you really figured something out, rather than having it all explained to you.
If you’ve played it, you know what I mean. If you haven’t, don’t waste time here, go buy it!
UPDATE: I should mention that Obsidian Entertainment, the company who made KotOR II, has also made many other games which people tell me are of similarly high or higher quality, and that many of the people who founded Obsidian worked on Planescape: Torment, which is, I’ve often been told, the ultimate in deep, philosophical gaming. I’ve never played any of these games, so I can’t comment on them. I will say that the reason I gravitated towards KotOR is that I tend to prefer Space settings to Medieval-Fantasy settings.