There are a wide variety of Bibles for many reasons. Some Christians have a difficult time understanding the English language, and so we have the Living Bible, the Contemporary English Version Bible (CEV), the New International Version Bible (NIV), the Living Bible Translation (LB), New Living Translation Bible (NLT) and others. These Bibles attempt to be more “readable” or more easily understood. As a result, when the translators come to portions of the Bible which are difficult to understand, they have to interpret some parts of the Bible. They add words and delete words from the original language.
The New King James Version Bible (NKJV) and the New American Standard Bibles (NASB) attempt to be as close to the original word order and word meaning as the Hebrew and Greek texts. Consequently, some difficult passages are hard to understand. But then the non-English reader has the opportunity to try to understand the meaning of the passage. This approach has the advantage of a translation closer to the original language and the reader does not have to be so concerned about the what the Bible is actually saying. It is important to remember that no translation can give us an exact word for word meaning. But the NASB and NKJV are the best.
Conclusion:
There are many Bibles available to Christians who read English. In short, the translators and publishers have different reasons for making different Bibles. But if you do not know Hebrew or Greek and you would like to read a Bible that is very close to the original language, then I would encourage you to read a NKJV or a NASB.