General synonyms:
* Delightful
* Pleasant
* Gratifying
* Satisfying
* Amusing
* Entertaining
* Fun
* Rewarding
* Exhilarating
* Stimulating
More specific synonyms:
* Relaxing: Calm, soothing, tranquil, serene
* Exciting: Thrilling, exhilarating, invigorating, stimulating
* Engaging: Intriguing, captivating, absorbing, fascinating
* Inspiring: Motivating, uplifting, encouraging, heartening
* Memorable: Unforgettable, striking, remarkable, extraordinary
Informal synonyms:
* Awesome
* Rad
* Sweet
* Cool
* Great
* Fantastic
The best synonym to use will depend on the specific context. For example, if you're describing a relaxing vacation, "soothing" or "tranquil" might be good choices. If you're talking about a thrilling rollercoaster ride, "exhilarating" or "invigorating" might be better options.