NVI all the way. (Nueva Version Interacional) It is easy to read, is a translation, not a paraphrase, based on the oldest and most reliable manuscripts, not the Textus Receptus, such as the Reina-Valera. The language of the RV is foreign to Latin America, using many words and verb forms that do not exist outside of Spain. The RV would be the equivalent to the KJV in the Spanish world. It is the preferred Bible, but I have met a great many Christians who do not understand it. For them it is akin to hearing a mass in Latin. It falls meaningless on their ears.
The point of putting the Bible into the common language was so that everyone could understand it.
The NVI is understandable to most literate persons, with an intermediate reading level in common Spanish. Being a thought for thought translation it also better renders colloquialisms and other hard-to translate thoughts out of the Greek into Spanish than word-for-word translations do. The is a lot on RV onlyism in Latin America, just as there is KJV onlyism in the ENglish world. In most cases this is people clinging to tradition and what they know, with very little actual academic basis for their arguments.
At the end of the day the decision is relatively simple. Is the reader’s reading level advanced enough to follow the RV? If not, then give him/her an NVI. If the pulpit Bible in their church is a RV, then find them an NVI-RV parallel Bible, so they can follow along with the pulpit, yet have a Bible they can understand for private study.
The best Bible is one that will be read.
Personally in English I use the NASB, while in Spanish I use the NVI.
Rivers Of Joy Baptist Church 