Heck, if there was only one version, we'd have to learn a whole other language to learn it, and that defeats the whole purpose of the Bible (to convey an attainable message)!!!
I own a few King James, an NKJ, an NIV, and an NLT.
The King James is nice for quoting and ornament, IMO. It's a bit too "old language" for me.
The New King James keeps the same feel as the King James, but in a little more modern terms, and the New Intertional Version is a great GREAT version that has enough common language that you don't get lost in reading it, but is still very thought provoking. If I am completely lost in the language, and not the meaning, my New Living Translation really helps straighten me out.
All of them = same message, but some have more palpable language than others.