General:
* Joyful
* Excited
* Thrilled
* Enthusiastic
* Eager
* Elated
* Delighted
* Cheerful
* Jubilant
More specific:
* Anticipatory (especially for something exciting)
* Exuberant (a lively and energetic excitement)
* Effervescent (a bubbly and lively excitement)
* Giddy (a light-hearted and playful excitement)
* Buoyant (a feeling of hopefulness and optimism)
The best word will depend on the specific context and the nuance you want to convey.