Nasty

The most appropriate antonym of the word "nasty" is praiseworthy.

• Nasty means "extremely unpleasant, disagreeable, or offensive."
• Praiseworthy means "deserving of praise or admiration."

The other words do not have the same meaning as "nasty" and are therefore not antonyms.

• Disgusting means "causing disgust or revulsion."
• Injurious means "causing injury or harm."
• Hamper means "to hinder or obstruct."