General Synonyms:
* Happy
* Joyful
* Merry
* Bright
* Lighthearted
* Optimistic
* Upbeat
* Cheerful
* Glad
* Delighted
More Specific Synonyms:
* Bubbly: Lively and enthusiastic.
* Ebullient: Overflowing with excitement and enthusiasm.
* Effervescent: Lively and sparkling.
* Radiant: Full of joy and happiness.
* Vivacious: Full of life and energy.
* Exuberant: Full of energy and excitement.
* Jovial: Full of good humor and merriment.
More Formal Synonyms:
* Cordial: Warm and friendly.
* Affable: Pleasant and easy to talk to.
* Genial: Warm and friendly.
The best synonym for "cheery" will depend on the specific context and the feeling you want to evoke.