There isn't a perfect one-to-one abstract noun for "nice." However, depending on the context of "nice," you can use these abstract nouns:

* Pleasure: If "nice" refers to a feeling of enjoyment.

* Kindness: If "nice" refers to a positive and caring attitude.

* Courtesy: If "nice" refers to polite and respectful behavior.

* Charm: If "nice" refers to a pleasing and attractive quality.

* Pleasantness: This is a more general term that encompasses all the positive aspects of "nice."

The best choice will depend on the specific situation and what aspect of "nice" you want to emphasize.