Which social media (Facebook, Twitter, Google+, LinkedIn, etc) is best for searching job?

Linkedin - There are industry professional available. Lot of job posting happens in Linkedin. You can use their premium services also.

Depending on the region and industry that you are targeting. But basically Linkedin is the starting point for everyone.

I THINK NON OF THEM YOU HAVE TO SEARCH FOR JOB BY WALKING, THIS SITES ARE GOOD BUT RESPONSE IS VERY LATE. 

For professionals, I prefer Linkedln because the provide detailed job description and qualification parameters for applicants,

I would say LinkedIn is the best, however, Bayt is also growing day by day so no harm in checking here for jobs as well. Also you might want to try visiting job sites such as monster.com to increase your chances of landing a job.

LinkedIn is probably the best, however, I say it depends on your profession. 

LinkedIn works best for me.