There is nothing like “Best Domain Name Extension” but yes, there are few that you should avoid. You can go ahead with any of the regular Domain Name extensions like .com, .net, or .me, but the most preferred extensions are .com and .net as they are cheap and easy to remember.
If you’re thinking from a Search Engine point of view, then the domain extension doesn’t really matter. It is widely said that .info domain extensions are used by scam sites and should be avoided totally but Google doesn’t specify this anywhere. Moreover, .info domain names are the cheapest.
But honestly, if I were you, I’d stay away from .info domain extensions and go with either a .com or a .net.
What have you finally chosen?