General:
* Pleasant
* Delightful
* Gratifying
* Satisfying
* Rewarding
* Amusing
* Fun
* Engaging
* Entertaining
More specific:
* For an experience: Exhilarating, thrilling, captivating, mesmerizing, inspiring
* For a person: Cheerful, happy, content, satisfied
* For an activity: Stimulating, absorbing, captivating, riveting, enthralling
Formal:
* Agreeable
* Delightful
* Gratifying
* Pleasing
The best synonym for "enjoyable" will depend on the specific situation and the feeling you want to convey.