What is the most important in a web site?

1.Templetes

2.SEO

3.Responsive(Mobile, Tablet and PC)

4.Less Loading time

5.User Friendly

easy use and fast to reach 

The most important in a website is the overall user experience. The purpose of a website is to serve as the company's online signature and therefore takes into account all forms of responsiveness, a reflection of the firm's status in the site's design and feel as well as overall utility.

1. Responsive
2. Call to actions
3. Good and simple content
4. Last but not the least Professional Pictures that describe your exactly your product
5. Finally SEO Properly

The website must be,1. User Friendly2. Responsive3. Well Codded and Designed4. Up to the Search Engine Criteria

At first, it should be useful. You should respect the 7 ergonomic criterias in your development. In addition, all website should be user friendly, respensive design and have nice options like multi language.