Dragon Age 3
The Witcher 3: Wild Hunt
Mass Effect 1 - 3
World Of Tanks
Warcraft 3 Dota Allstars$$ \text{Efficiency} = \left( \frac{\text{Energy Output}}{\text{Energy Input}} \right) \times 100% $$
TES V: Skyrim
$$ \text{Efficiency} = \left( \frac{\text{Energy Output}}{\text{Energy Input}} \right) \times 100% $$
TES IV: Oblivion
Fallout: New Vegas
Sacred 3
Divinity Original Sin
$$ \text{Efficiency} = \left( \frac{\text{Energy Output}}{\text{Energy Input}} \right) \times 100% $$