If you've got a good imagination (and used to have fun playing with regular toys when young) you'll probably maximize the entertainment potential of every game. All you need are the right tools.
I've already spent hours playing games like The Sims, Fable, Medieval Total War 2, Oblivion (,and many others) by mixing the gameplay itself with an imaginary narrative and exhilarating dubbing, all fabricated by my twisted mind.
That's the slight freedom that many games make available, but not everyone makes good use of. Simulate conversations between your Sims, Battle Cries in Total War, or mundane tasks in both Fable and Oblivion. After all, you're playing and already role-playing, even if minimally; why not maximize it?