While there is a short list of popular countries, there is no one single offshore jurisdiction that is the best for all businesses. Selecting the best offshoring jurisdiction depends on the type of business and the desired balance of cost, tax impact, reporting requirements, privacy, and asset protection.
For example, a business with employees has to take into account foreign employment laws, ability to obtain work visas, and local talent. The Cayman Islands is not the best jurisdiction for that. Hong Kong, as another example, makes it easy to register a business but requires audited annual financial statements.
Selecting the right country to form your offshore company is the first and most important step.