"Dear + name" is the standard opening for a letter except among friends, when any number of alternatives exist. Occasionally you may see a "To whom it may concern:" in a formal circumstance when the addressee's name is unknown, and there may be times when this phrase has some legal significance, I just don't know. But even in very formal situations with an unknown addressee, people use "Dear Sir or Madam:", in my experience.
I've never seen "Good + name". It might be used among friends, but even then, it would be consciously odd, a bit of a joke.