Simple Answer
If you want a simple answer, I recommend the NIV due to it being: a more readable translation, easy to find in online and brick and mortar stores, and suitable for both entry level and advanced study. The publisher is very big and well established and has both legacy study tools as well as newly released ones as well.
General Answer
I recommend buying a MacArthur Bible Commentary or a Tony Evans Bible Commentary for practical advice on how to live the Bible. I also recommend buying a Moody Bible Commentary or Baker Illustrated Bible Background Commentary for academic and cultural insights, to determine what the Bible is saying to our culture. I also recommend getting a Super Giant Print Bible, for when you are reading it at length and for when you get older. I recommend these commentaries rather than study bibles as they are cheaper, easier to read in terms of font size and paper opacity, and often provide more information.
Font Sizes
Standard font size for print Bibles now is 7.5 - 9 Point, Large Print is now 9.5 - 11 Point, Giant Print is now 11.5 - 13 Point, and Super Giant Print is now 14 - 17 Point. The fonts are usually large ones like Palatino and are optimized for reading. Sizes do vary widely as there is no set point size for any of these Bible font size names.
Sewn Bindings
The most important factor in buying a Bible is if it is sewn or smyth sewn. This means it will not likely fall apart easily and this is how it was always done traditionally with hardcover, leather, or faux leather. The NLT, although a great translation, was instead glued and did not hold up to long term use, for a number of years. They have recently made all their Bibles sewn again.
NLT Filament series Bibles were always sewn. Thomas Nelson NKJV Bibles are all sewn since 2017, if they retail for over $10. As far as I have experienced, Holman’s CSB Bibles and Crossway’s ESV Bibles are always sewn. Most Zondervan NIV Bibles say they lat flat, which I think refers to being sewn as well. Other publishers sometimes choose glue instead of sewn, so always check about it.
Paper Opacity
Another important factor is page opacity. Most Bibles now have very thin paper, unless you get a Journaling Bible or a LSB Bible (made by the same group as the ones that made the NASB). There is something called Line Matching which makes up for this to some degree. Cameras amplify this so you cannot go by pictures.
Imitation Leather
I do not recommend buying hardcover online or leather anywhere. Hardcover Bibles can be dented in shipping and also can trigger security audits because some are so big. Leather today is both hard to verify, the leather is lower quality than in the past, and it is much more expensive without giving enough durability to be worth the cost. You can now get imitation leather, which is not only durable, but can also be dyed and embossed, to make it look more artistic, so you have a choice besides plain brown or plain black, in masculine styles.
Premium Bibles
If you still want leather, the only thing that is not imitation leather will either say genuine leather or the animal it comes from leather, like goat skin leather or buffalo skin leather. Be prepared to spend at least $100 and as much as $500, depending on who the publisher is. They are also not usually in the largest font sizes either. These are often called Premium, Heirloom, or Pastor’s Bibles, but not Premium Value Bibles.
Gilding
Gilding is something most people would not care about but it serves a practical purpose in that it is resistant to silverfish bugs. It will shed glitter like material though. You don’t have color Bibles very often that are gilded.
Bible Reviews
Youtube has many good reviewers of Bibles that will give you much more information about how to determine what Bible or Study Bible is best for you. You cannot go by the colors in the Amazon photos as they are misleading both for the covers and interior. Most of the red looking Bibles are often more of a pink in “real life”. Many of the leading Bibles and Bibles study tools are very good, but some of them have print defects like missing pages. Also, avoid getting Bible references that are in multiple volumes online, as Amazon often mixes them up and your set won’t be complete.
Budget Friendly
If you are looking for a solid Bible, at the lowest cost possible, while still being high quality, you can find what is called Gift Bibles, Value Bibles, or Pew Bibles. Hardcover is also a good option to reduce cost, but I would avoid that for a thick study Bible. You don’t usually get any commentary, notes, or cross references, so it is just the Bible and nothing else.
Ultimate Bibles
The ultimate Bible I think is the multi-volume Readers Bible (excluding the paperback versions) and Family Bibles as they often have sewn bindings, larger print, and thick paper. The trade off is that they are often heavier and bigger in height and width. There used to be a lot of notes in separate books called Commentaries but most today are Study Bibles, which are easier to find as they are more popular amongst non-scholars.