I think death note would win because if you want someone to die then boom write their name that simple. and even more simple if you have the ability to see their true name etc etc with the special eyes.
But the whole process of the hell girl thing seems like it would take too long to get done. BUT it might be better than just dying because in death note the person dies afterlife isn't exactly horrid but in hell girl they are legit sent to hell to be tortured.