Formal:
* Exemplar: This emphasizes the person's quality as a perfect example.
* Ideal: This highlights the aspirational aspect of the person's qualities.
* Prototype: This focuses on the person being a pattern or model for others to follow.
Informal:
* Inspiration: This emphasizes the motivational aspect of the person's influence.
* Mentor: This implies a more active role in guiding and supporting others.
* Icon: This suggests a figure of great admiration and influence.
The best synonym will depend on the specific nuance you want to convey.