General synonyms:
* Eloquent
* Articulate
* Moving
* Evocative
* Emotional
* Poignant
* Vivid
* Powerful
* Meaningful
* Significant
* Communicative
* Illustrative
More specific synonyms:
* Dramatic (for something visually or emotionally impactful)
* Lyrical (for something poetic or musical)
* Eloquent (for something verbally fluent and persuasive)
* Intense (for something strongly felt or expressed)
* Passionate (for something filled with emotion and enthusiasm)
* Animated (for something lively and energetic)
* Vibrant (for something full of color and life)
The best synonym for "expressive" will depend on the specific context and the nuance you want to convey.