For describing how something is done:
* Successfully: He completed the task successfully.
* Efficiently: She worked efficiently and finished early.
* Thoroughly: The house was thoroughly cleaned.
* Carefully: He handled the delicate vase carefully.
* Skillfully: The artist painted the portrait skillfully.
* Properly: Make sure the equipment is properly assembled.
For expressing good health or condition:
* Nicely: She is feeling nicely today.
* Healthily: He eats healthily and exercises regularly.
* Strongly: He is feeling strongly after his illness.
For expressing a high degree or intensity:
* Very: He is very good at his job.
* Extremely: The movie was extremely entertaining.
* Highly: The restaurant is highly recommended.
For expressing agreement or affirmation:
* Certainly: I certainly agree with your point.
* Definitely: I will definitely be there.
* Absolutely: That is absolutely correct.
The best adverb to use will depend on the specific meaning you want to convey.