Ideally, if we all could learn the original languages, we could read a version of the Bible based on these languages. Realistically, except for those trained in these languages, our choices are limited to English translations. A translation refers to the process of expressing the meaning of a word, a phrase, or a thought from one language into another language.
Today's English Bible reader has many choices within a spectrum or continuum. On end are "word-for-word" translations. These attempt to translate the actual words from biblical Hebrew, Koine Greek, Aramaic, and their respective grammatical structures. As literal as these translations are, there are instances where there are no equivalent English words or comparable grammatical choices. The most literal "word-for-word" translations would include Hebrew or Greek interlinear Bibles where the English words appear right below the Hebrew or Greek text, but these are very difficult to follow in English. Somewhere around the middle of the spectrum are the "thought-for-thought" translations. The emphasis is on translating the author's thoughts and not merely his words. Finally, on the other end are the paraphrases which are neither "word-for-word" or "thought-for-thought" translations. Instead, they attempt to restate the author's ideas by asking “how would author say the same thing today,” including references to contemporary culture and colloquial words.
Most translations fall somewhere between these two ends. For example, the New American Standard Bible is closer to a "word-for-word" translation.
The New International Version has elements of a word-for-word translation but sometimes uses a thought-for-thought translation. Some of the newer translations, such as The Message and The Passion are paraphrases.
So, which is the best translation? It depends on what you are using your Bible for.
If you are doing a word study, a "word-for-word" translation along with a Bible concordance may be your best choice.
If you are doing a topical study, a "thought-for-thought" translation may be your best choice.
If you are reading the Bible devotionally, a paraphrase may be the best choice.
Many Christians have more than one Bible for these various uses.
The best translation is the one that you hear the Master's voice through the illuminating ministry of the Holy Spirit.