unless you enjoy pretending you're in films, nothing.
i do, so i turn mine off
what i actually mean to say is, without agressive driving, you won't see a massive difference, and probably won't notice at all unless you enjoy driving quickly / pay a hell of a lot of attention to your car. for example, on a wet roundabout at slow speeds, the traction control may slightly limit power and step in. but if you're on a lazy, half asleep drive to work, you probably won't notice. boot it in first out of a junction in the wet with it turned on, then do it with it off.... you'll notice the difference rather quickly!