The two best translations into English are the Douay Rheims, which was published before the KJV, and the Revised Standard Version-2nd Catholic Edition. These two are the most used by scholars and theologians in terms of English editions.
The official version of the Bible for the Catholic Church is the Latin Vulgate, 2nd Edition. All translations into any vernacular language must be as close as possible to the Latin Vulgate translated according to the principles of translation. One always loses some meaning when translating into any language. Thus, study of the Latin Vulgate and the Original Languages is necessary.
A good summary is found in the article, "
Bible Translations Guide."
Also see a list and comments in the article, "
Bible Versions and Commentaries."
Here are the official principles of translation set by the Vatican, "
Liturgiam Authenticam" and a
summary of that long document.