General:
* Pleasure
* Delight
* Gratification
* Satisfaction
* Happiness
* Fun
* Amusement
* Merriment
* Exhilaration
* Contentment
More specific:
* Physical enjoyment: Bliss, rapture, ecstasy, elation
* Intellectual enjoyment: Stimulation, fascination, intrigue
* Social enjoyment: Companionship, camaraderie, fellowship
* Artistic enjoyment: Appreciation, admiration, awe
* Spiritual enjoyment: Fulfillment, peace, serenity
Informal:
* Fun
* A blast
* A good time
* A kick
* A hoot
The best synonym for "enjoyment" will depend on the specific context and the intended meaning.