As others on this thread have mentioned, the NLT, while reasonably good at what it set out to do (allowing the translators a bit more leeway in communicating underlying ideas) it is still a paraphrase. Any paraphrase translation tends to amplify the underlying perspectives of the translators, and thus is probably *not* a good translation to be used alone. Actually all translations suffer from this 'translator's perspective' problem (there are some really glaring examples in the KJV, f'rinstance) so the best way to study Holy Scripture in English is to use two trustworthy translations together.
A number of good suggestions have been made by others on this thread, but I'll throw in my 2 cents' worth anyway. If you're comfortable with the NLT, you might consider using the NASB as your other translation. The reason I suggest this is because the NASB follows just the opposite translation philosophy. They try to be as literal as possible, even to the point of listing multiple alternate translations for individual words. The contrast between these two translations should allow you to grasp more of the full meaning of the text much more easily than either one alone. Just be certain to get yourself a copy with all of the side column (or center column)notes and footnotes; and choose a copy that's in a LARGE typeface - at least if you are *ahem* over 40 and don't want to squint a lot at the footnotes.
Other good nonparaphrased translations are the ESV and NKJV...the NIV is okay, but there are portions of it which tend to slide over a bit toward a paraphrase, without really crossing the line...much.
In any case, the bottom line is that, given that one can't work in the original languages (and *I* certainly can't) the practice of using at least two different translations provides a much better understanding of the text than would be possible with either one alone.
Wise exhortations about multiple translations to study.
And, I still have an Amplified which I frequently consult--though I probably do it more online, now.
It's not uncommon to look at a verse in 5-7 different translations.
I think I lost my Greek Interlinear NT long ago along the way somewhere.
I do, however, think that several paraphrases are probably, on summary, more accurate than a lot of word for word translations. And, you seem to imply that word for word translations have no paraphrases in them--which is inaccurate, to my understanding.
I suppose it's likely that if one disagrees with the theological perspective of the translators using significant paraphrasing in their translations, one is likely to find great fault with the result. And, vice versa.
I have a lot of sympathy with Peterson's perspective and a fair amount with the NLT.
My NIV's are all older versions as I recall.