What is the best SAFe certification for a Scrum Master?

The best SAFe certification for a Scrum Master is SAFe Scrum Master. Alternatively, non-SAFe certifications include those from Scrum.org including the Professional Scrum Master (PSM-I), which is highly regarded.

Alternatively, taking the SAFe® Leading SAFe 6. 0 or SAFe® 6 Agilist certification is also popular. Additionally, you might consider the Agile Fundamentals (ICP) from ICAgile or the Certified Scrum Master (CSM) from the Scrum Alliance.

For those with a focus on technical agility, the Professional DevOps Foundation certificate is noteworthy. There are also other methodologies such as Kanban that might be relevant.