Hanging drywall can be a big chore. Make it easier on yourself by using screws. Screws have much better holding power than nails and can be faster to install through the use of a drill. They can also be counter sunk making mudding easier for a finished look. 

While nails are often cheaper than screws, they can loosen with age and pop out over the mudding, which can crack your paint and ruin the finish of your wall. Using screws will help you complete your drywall project faster and make it last longer.