Thank you for the question, “Which English version of the Bible has the best translation of the original text?”
For my own critical study of the New Testament, I used the NASB-NIV Parallel New Testament in Greek and English. It is an excellent book for one can read the translations of the Greek words as well as see the NASB and the NIV translation.
For the critical study of the Old Testament, I like reading the Analytical Key to the Old Testament in English. This allows me to cross reference into Strong’s or Young’s Concordance for my information.
However that is “old school” as there are excellent tools online for research. I use them as well. Information is not the issue, but discerning the answers and pondering various views.
For more perspectives: