Thank you for the question on the best translated version of the Bible, “What is the most accurate, complete, and authentic version of the Bible?”
This question is a very common one. The most accurate translation of the New Testament is the NASB-NIV Parallel New Testament in Greek and English by Marshall in my opinion. It has the Greek text with two translations for comparisons of the Greek translation in the New American Standard Bible and the New International Version. For the Old Testament, I used the Analytical Key to the Old Testament by Owens for a more critical study.
There are many very good translation online that one can read today. It depends if one wants a more literal translation or a dynamic translation of the Biblical text. Most modern versions are dynamic or contemporary/modern translation.
SUMMARY: For critical study, I recommend a Hebrew-Greek translation in English but for general reading most modern translations will suffice.
For more perspectives:
https://www.quora.com/What-is-the-most-accurate-complete-and-authentic-version-of-the-Bible