Since 1974 I have use approx. 18 different Bibles. I have also done research on the bibles themselves. This is not my opinion but based on facts, the King James Version Bible is the worst bible today. Yet it is the most used/popular today. My question, why is that? If people believe the Bible is the absolute word of God and the King James is full of errors and the people believe all those errors what does that tell those that know the difference?
The King James Version is popular because for many years some churches (Anglican/Episcopal, and others) would not allow use of any other version. If it is still the most widely used English translation, which I doubt, it is primarily because older Christians continue to use it. Currently, the New American Translation is probably the English translation most widely used by Roman Catholics, and the New International Version the most widely used by everyone else.
There is no perfect translation. There are better and worse. (Please see What Does the Bible Say About..Bible Versions" for my previous answer about the advantages and disadvantages of some versions.)
The King James Version was good for its time (and very controversial). It is still a fairly accurate translation. The problem is that the language has changed considerably in the last 400 years. Some of what seem to be bad translations are due to reversals in the meaning of words in English. The other problem with the King James Version is that it was translated based on manuscripts available 400 years ago. There have been discoveries of earlier manuscripts that may have brought about some minor changes.
The King James Version is not the worst version in English available today. That honor clearly goes to the New World Translation, with The Living Bible a distant second. The more I read the New International Version, the less I like it.
One problem of English versions in general is that the more somebody tries to make it easily readable, the less accurate it becomes. The New American Standard Bible is one of the most accurate translations, but the English becomes a little too formal at times, and so doesnít read well out loud. For study, though, it stands out as one of the best.
With few exceptions, the best Bible is one that you can understand. Anyone who was not raised on the King James Bible or William Shakspere may find the 17th Century English difficult to understand. With all its errors, the NIV may be the best for most English readers. I donít even try to evaluate translations in other languages, because my Spanish and German are minimal and everything else is virtually nonexistent to me.