There are several reviews of the errors found in the NIV, and these can be found with an internet search. There is "The NIV - Simply a Bad Translation" here
But an examination of some of verses in the various translations will point out a clear bias on the part of the committee which oversaw the NIV translations. There are at first glance what may appear to be slight differences, but when carefully examined are glaring in implication.
Phil. 2:7, in the KJV reads -
"But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men:"
and in the RSV reads -
"but emptied himself, taking the form of a servant, being born in the likeness of men."
and in Young's reads -
"but did empty himself, the form of a servant having taken, in the likeness of men having been made,"
But, the NIV has translated it -
"rather, he made himself nothing by taking the very nature of a servant, being made in human likeness."
And, the impact is quite different. The entire discussion of Phil. 2:5-11 is the glory of Christ unto whom all must kneel confessing that Christ is Lord. That He temporarily put off the "form of God" - vs. 6 - take on the form of a servant in vs. 7 did not make Him "nothing".
If something or someone is nothing, it / they do not exist. If someone is nothing, then are they important, or someone we should ignore?
The translation of the NIV makes Christ appear to be without authority, and contradicts other scripture that affirms His nature and deity as the Son of God (John 10:30; John 20:28; 1 John 5:7). It also implies that as He took on the likeness of a man, that therefore man is also nothing. This is not just a bad translation, but a completely false translation, and if not outright blasphemy it certainly borders on it.
This is not a one-off. 2 Pet. 2:8 correctly translation in Young's is
" and a stone of stumbling and a rock of offence -- who are stumbling at the word, being unbelieving, -- to which also they were set;"
but in the NIV reads as,
" A stone that causes people to stumble and a rock that makes them fall."
Again, a subtle variance but one that makes it appear that Christ is the one who makes man to stumble, when in fact it is man that takes offense at the Word and stumbles / falls of his own will.
The NIV promotes the theology of "once saved always saved" by changing the subjunctive mood of "should" to the indicative mood of "shall" in John 3:16. Again, subtle, but a lie.
The NIV also changes the "only begotten Son" in John 3:16 to "one and only Son". Christ was begotten of God at His resurrection from the dead (Acts 13:33; Heb. 1:5) This was uniquely attributable to Christ. But, he is not the one and only, as we who are in Christ - baptized into His sacrifice - are also sons of God (John 1:12; Rom. 8:14; Gal. 4:6).
There are many more problems with the NIV, and they are severe.
See also:
The N.I.V. Infection here
The NIV Report here
Bold emphasis is mine.