Before you read this post, it really would be a good idea to read this article by the same name on The Aquila Report, written by Greg Gilbert. The reasons he gives for multiple Bible versions in this article are all true and accurate. I would add one more reason there are so many English versions. That is the litigious nature of our society.
A publishing company owns the rights to the translation of the Bible that they produced or that they purchased. So when their authors write their books, citing scripture from the owned translation, there is no copyright worry. If they cite a different translation, there may be a fee requested by the owner of that translation, cutting into the profits of the book. Different publishers have different allowances for the use of their translation.
I believe the King James Version is open source, so it can be quoted without worry by any publishing company. That explains why this is the version quoted most often in movies and television shows. That also explains why you can find copies of the KJV in discount stores.
Genesis 50:20 ESV
As for you, you meant evil against me, but God meant it for good
The litigious nature of American companies did play a role in the multitude of translations. And while it is not good that we are so quick to let a secular court settle differences between Christian publishing houses, God has used this to provide many faithful translations of the Bible, which can be used in a myriad of ways to build His church.
To whom much is given, though, much is required. As the body of Christ, we have resources that were unimaginable in past generations. We have a responsibility to study the word diligently, to meditate on the light that has overcome the darkness, to use these translations to the glory of God. And this message must reproduce both locally and afar.