what do do you think is the greatest piece of evidence for the big bang to me it’s red shift?

Question: what do do you think is the greatest piece of evidence for the big bang to me it's red shift?
- Keywords:
  big bang,
  evidence,
  red shift
Asked by 676prtj25 to Nicolas on 19 Jun 2017.
- Nicolas Labrosse answered on 19 Jun 2017:
  
  It’s an excellent point: the fact that all galaxies are moving away from each other and show consistently this redshift is a great piece of evidence that the Universe is expanding, which is a result of the Big Bang. Another great piece of evidence is what we call the Cosmic Microwave Background Radiation, which shows that the Universe’s temperature is about 2.7 K (2.7 degrees above absolute zero) everywhere, and to a very high precision. This observation is in full agreement with the Big Bang theory.

Question: what do do you think is the greatest piece of evidence for the big bang to me it's red shift?