how i become best developer

Hi Pradip,

There is no straight way to be a good developer. As Mahesh is already given lots of suggestions and if you will follow this then nobody can stop you to become a Good Developer. 

In my point of View "Continuous Learning" can make you a good developer, make a necessary habit of learn like we do other stuff eat,sleep, job etc.

Read this article of Mahesh, it will also help you. 

http://www.c-sharpcorner.com/UploadFile/mahesh/get-ready-for-your-next-job-don%E2%80%99t-wait/

Yes Girish, Certification can help you. You can look into below URL for latest certification

https://www.microsoft.com/learning/en-in/mcsd-web-apps-certification.aspx

Experience is the only way to become a good coder. Follow best practices and standards and write as much code you can. Work in good companies and projects who have good developers.

Here are some tips

• Read lot of books, articles and documentation.
• Carefully pay attention to how experienced developers write code. Definitely, master code written by Microsoft in MSDN samples and documentation.
• Read advice on C# Corner 
• Hang out with the best developers
• Debate, read, write, learn and share
• Stay upto date with new versions. Again, read latest news, releases etc.

Here is one article you want to start with: 
http://www.c-sharpcorner.com/UploadFile/mahesh/how-to-become-a-C-Sharp-programmer/ 

There are more articles/blogs in Career Advice section. 

Good luck!