In general NLT is considered a very good version for general casual reading because it is a good paraphrase. Some will use it for devotions. But for serious Bible studies it isn't as good since it takes quite a bit of liberty in terms of sentence structures - many native Neglish-speaking Bible teachers recommend NASB (New American Standard Bible, which is different from the Catholic NAB) since NASB is the most word-to-word translation from the original Greek and Hebrew.
I personally recommend NKJV and NIV for all purposes because their English is simple enough for devotional uses and for ESL people (such as I myself am), and its sentence structure is similar enough to the original Greek and Hebrew for Bible studies. Only use the KJV as your primary Bible if you took plenty of English Literature courses in high school or university.
Old versions of the NIV are OK, but the current version has been made 'politically correct' at the cost of accuracy.
Gender-neutral NIV revision announced; Bible society drops translation accord
Jan 28, 2002
By Art Toalston
NASHVILLE, Tenn. (BP)--A Jan. 28 news release announcing a "Today's New International Version" of the Bible reports that the TNIV entails a "7 percent change" from the widely used New International Version, or NIV, published by the International Bible Society and Zondervan.
http://www.bpnews.net/bpnews.asp?ID=12625