* ἀγαθός (agathós): This means "good" in a general sense, and could be used to describe a good-natured person. However, it's quite broad.
* εὐγενής (eugenḗs): This means "noble" or "well-born," but it often implies a good-natured disposition associated with good breeding and character.
* φιλάνθρωπος (philánthrōpos): This means "human-loving" or "philanthropic," suggesting a kind and benevolent nature. This is probably the closest single word.
* χαριτωμένος (charitōménos): This translates to "gracious" or "charming," and can imply a good-natured and pleasant personality.
The best choice will depend on the specific context. For a general, everyday use, φιλάνθρωπος (philánthrōpos) is likely the most suitable.