The King James (KJV) Bible, as long as contains all 73 books (most only contain the 66 books of the Protestant canon), is pretty decent, but it is better to have a Catholic Bible, such as the Revised Standard Version Catholic Edition (RSV-CE or NRSV-CE), if you prefer modern English, or the Douay-Rheims (DRB|DRA) (if you prefer the King James English), or the New American Bible Revised Edition (NABRE) (which hews closely to the lectionary read at Mass).
Biblical scholarship has advanced much since the King James (KJV) was translated, and it is good to get the benefit of that scholarship. More manuscripts have been discovered. But the bottom line is, as someone once said,
The best Bible to buy is the one you're going to read.