The most important dharmashastra is Manusmriti. Here's why:

Manusmriti is an ancient Hindu text that lays down the rules and regulations for leading a Dharmic life. It is also known as Manav Dharmashastra. The text is attributed to Manu, who is believed to be the progenitor of humankind according to Hindu mythology. The Manusmriti is considered to be the most important dharmashastra for the following reasons:

1. It covers all aspects of life: Manusmriti is a comprehensive text that covers all aspects of life, including personal conduct, family life, social norms, and governance. It provides guidelines for individuals on how to conduct themselves in various situations and also lays down the duties and responsibilities of different members of society.

2. It is widely accepted: Manusmriti is widely accepted by the Hindu community as a source of guidance on leading a Dharmic life. It is considered to be one of the most authoritative texts on Hindu law and ethics.

3. It has influenced other texts: Many other texts and commentaries on Hindu law and ethics have been influenced by Manusmriti. It has had a significant impact on the development of Hindu legal and social systems.

4. It is still relevant today: Despite being an ancient text, Manusmriti is still relevant today. Its principles and guidelines can be applied to contemporary situations and can help individuals lead a Dharmic life in the modern world.

In conclusion, Manusmriti is the most important dharmashastra because of its comprehensive coverage of all aspects of life, its widespread acceptance, its influence on other texts, and its continued relevance today.