The first season!
Many people agree that the first reason for the 13 Reasons Why is by far the best season.
The first season was accepted by many, and it was a massive success. This led to the production of subsequent seasons. However, the series is no longer as good as it was at the beginning.
Also, the first season was based in the novel Thirteen Reason Why by Jay Asher. Over time, more storylines and cases were added to the series, and all of these did not meet up to viewers' expectations.
Netflix has announced that a new season (season 4) is already produced. It was also made known that the new season will be the last season to serve as closure for the television series.