The main problem is a thing called “dynamic equivelency” What it is, is, there are some words or ideas that cannot be translated directly from one language to another. For example. In Russian there is no word for coal. The closest we can come to it is ‘the rock that burns’. Same thing for Biblical translation. Some Christian sects see a thought, word, or idea one way, another sect sees it differently. So with the case of the NIV, different sections of the most original scripture we have on hand were sent out to different committees. Long story short, of all of them they came to a consensus of what is closest to the original thought that could be translated into English. It took years to accomplish and about all the main denominations took part.
I have nothing against the NIV, I got saved on it and cut my biblical teeth on it, but if anyone wants to go to a deeper level of Bible study and reading, get a literal translation. Many above have been mentioned. I am now, definitely sold on the ESV. The more I read it the more I fall in love with it. I have also spent lots of time in the KJV, NASB, NKJV and RSV and I would not hesitate to recommend any of them. My Catholic brethren can recommend Catholic translations, and several have above. Personally though, I've fallen hard for the ESV.
Hubby and I went to a meeting this week about the changes coming in the New Missal for the Roman Catholic Mass. The Monsignor doing the talk mentioned Dynamic Equivalency, and how it had created so much angst among so many. They used Formal Equivalency for the new version to eliminate the personal biases that were prevalent in the previous translations, and to hew more closely to the original meanings. He also mentioned the changes being made in the NAB, for the same reasons.