Strong emotion:
* Ardent: Shows intense and enthusiastic feeling.
* Fervent: Having or expressing great warmth and intensity of feeling.
* Zealous: Having or showing great energy or enthusiasm in pursuit of a cause or objective.
* Intense: Having or showing strong feelings or opinions.
* Fiery: Characterized by intense emotion, passion, or anger.
* Ebullient: Full of energy and enthusiasm.
Deep interest:
* Enthusiastic: Having or showing great excitement and interest.
* Keen: Having or showing a strong interest.
* Devoted: Having or showing strong loyalty and affection.
* Engrossed: Completely occupied by something to the exclusion of all else.
Strong desire:
* Yearning: A feeling of intense longing for something.
* Craving: A powerful desire for something.
* Thirsting: Having a strong desire for something, especially knowledge or experience.
Other related words:
* Animated: Full of life and energy.
* Invested: Having a strong personal interest in something.
* Motivated: Having a reason to act or behave in a particular way.
The best word to use will depend on the context of your sentence.