Right off the bat, the most infamous translation decision the NWT translators made was John 1:1.
"In [the] beginning the Word was, and the Word was with God, and the Word was a god." (NWT)
Attentive readers will instantly notice the article "a" before the last word of the verse (not to mention the lower case "g" in "god"). What's going on here? Well, the Jehovah's Witnesses don't believe in the Trinity, and so they point out that the first "God" (with the definite article preceding it in Greek) should be translated differently from the second "god," which lacks an article in Greek. However, just a few verse later, in John 1:13, the NWT contains the phrase "but from God." That "God" [theou (Θεου) in Greek] also lacks an article, but the NWT translators stuck with the traditional rendering. In short, they changed the traditional rendering when it was theologically convenient to do so.
Beyond the theological bias present in the NWT, there are several other difficulties with the translation. JW theology also has eschewed use of the cross as a Christian symbol; JWs believe Jesus was "impaled on a torture stake." Reflecting this theology, the Greek word σταυρος (stauros) is consistently rendered "torture stake" in the NWT, rather than "cross." I suppose there may be some legitimate room for argument on this topic, but nonetheless, it's a bit unsettling for the typical Christian reader.
One convention in the NWT that comes from a valid motivation is the use of the second-person plural pronoun ("ye" in older English versions, such as the KJV). When the pronoun "you" is plural in the Greek, the NWT uses YOU (all caps). The only problem here is that the average reader sees YOU as emphatic type, so reading "Happy are YOU when people reproach YOU and persecute YOU and lyingly say every sort of wicked thing against YOU for my sake" is a bit awkward.
Finally, in matters of English style the NWT falls short of being a readable English translation. The reader constantly encounters all kinds of oddly worded phrases. Here are just a few examples:
- "When YOU are fasting, stop becoming sad-faced like the hypocrites..." (Matt. 6:14)
- "For Jehovah is taking knowledge of the way of righteous ones..." (Psalm 1:6)
- "For at present we see in hazy outline by means of a metal mirror, but then it will be face to face." (1 Cor. 13:12)
- "But he was being pierced for out transgression; he was being crushed for our errors." (Isa. 53:5)
The reader will also notice the use of "Jehovah" for the name of God. This is, of course, a major theological point for Jehovah's Witnesses (as their name implies). The problem is, there has been abundant research that indicates that "Jehovah" was never used by the Jews as the name of God, and was in fact due to faulty reasoning on the part of medieval scribes, who combined the vowels from "Adonai" (Lord) with the consonants of the Tetragrammaton (YHWH). Still, the NWT is not the first English translation to use the "Jehovah" convention, and it is certainly the least of the problems with the translation.
Jehovah's Witnesses used to pretty much stick with the King James Version in all of their literature, and you will still find KJV renderings mixed with NWT renderings in modern JW tracts. It seems that they use different versions when it is convenient to do so: I'm sure they aren't the only sect to do so, but it does seem a bit disingenuous to me. You can see more of the NWT for yourself at the official JW site: clicking on the "Read the Bible Online" link will take you right to the NWT. Although I may be inciting the wrath of occasional JW readers by criticizing the NWT, I truly believe it is a version to "handle with care."
[P.S. I truly do not mean to use the term "JW" in a pejorative sense. It's simply a lot easier than typing "Jehovah's Witness" over and over. I apologize if it causes offense to anyone.]