Since getting the Playstation 3, I've used it for playing music files, for playing DVDs and Blu-rays. Oh, and we've even used it for playing a game. Once.
The game in question is "Lego Star Wars 3: The Clone Wars", which may potentially tell you something about me, since it's a game aimed at kids. Doesn't matter - I really enjoy all the Lego games. The truth is, I find most modern games really frustrating. Over time, they've added more and more to the interfaces used, so that playing the games becomes ever harder, and you need hundreds of hours of practice to become halfway decent... and I don't have hundreds of hours to dedicate to something like that (not to mention the risk of addiction, which for me is very real). Lego Star Wars is nice and simple, and I can just about handle it.
But one of the fascinating things about playing this game is the different approaches that LC and I take to the game. She likes racing through the levels, completing the 'story' part of the game fairly quickly, and calling it done. Me, I quite like taking my time, seeing the sights, and maybe completing some of the other challenges in the game.
What is particularly excellent about the Lego games is that they support both approaches. There are a few puzzles that you need to solve to complete the various levels, but these are fairly simple. Then there are more advanced puzzles you need to solve to unlock some of the other objectives in the level - these are often much more complex. And then there's one higher level of puzzle, used to unlock the little "Easter Eggs" hidden throughout the game that aren't part of any formal objective.
Basically, you can invest as much into the game as you want, and it will support you. I find that excellent.
(That my thoughts have also been straying towards the issues involved in creating a really good RPG adventure is not entirely incidental...)