General happiness and delight:
* Happiness
* Delight
* Pleasure
* Gladness
* Exuberance
* Cheer
* Mirth
* Jubilation
* Rapture
* Ecstasy
* Bliss
* Contentment
* Satisfaction
* Elation
More specific emotions related to joy:
* Excitement: Thrill, exhilaration, enthusiasm
* Warmth and affection: Love, fondness, tenderness
* Triumph: Victory, success, accomplishment
* Peace and serenity: Tranquility, contentment, peace of mind
* Awe and wonder: Amazement, wonder, astonishment
Words for expressing joy:
* Rejoice
* Celebrate
* Revel
* Exult
* Beam
* Smile
* Laugh
Words for describing something that brings joy:
* Delightful
* Wonderful
* Joyful
* Pleasant
* Charming
* Enchanting
* Heavenly
* Euphoric
The best synonym will depend on the specific context and the type of joy you want to convey.