For the average person, it is a good idea to make sure that at least one of your Bible’s is a good study Bible. This main Bible should be from the family of “essentially literal” translations (NAS, ESV, NKJ). To help in your study, having a second and possibly even a third Bible can be very helpful. One of those could be a “thought for thought” (NIV, HCS) and the third could be a paraphrase (NLT, Message, etc).
For the ESV, we would encourage you to get something like the MacArthur ESV study Bible. For children and young teens, you might want to consider the ESV ‘Following Jesus Bible’.
New American Standard
For the NASB, we would encourage you to consider something like the Ryrie Study Bible or the MacArthur Study Bible.