NintendoPie on 18 March 2013
Most games that go below 20-25 hours aren't worth it. (Unless done right. Like most 2D Platformers.)
Anything above 30 Hours would be pretty good for most games.
Games like Pokemon, with 100's of hours of gameplay, are absolutely awesome. (I know this list wasn't exactly what you were looking for but... deal with it! It's hard to be specific about these types of things.)
As you can see, I don't really play FPS games as they are way, way too short and boring. (In my opinion, of course.)
