From my "What is a Book?" course, based on the eponymous debate, especially when it came to classifications from physical books and e-books, I learned about what made those two formats different. However, I want to argue based on my personal preference. In my case, I prefer physically-bound books, whether they would be paperbacks or hardcovers.
No matter how many rearrangements there are on a bookshelf, there will always be new vivacious array of juxtaposed colors from the spines.
It is for that reason why Director David Mamet wrote about the juxtaposition of shots in film in order to create a new meaning for the audience, which is what made, by his knowledge, documentary films so interesting. He stated that all film-makers should want to become documentary film-makers, while I would argue that all book lovers should want to become librarians.
It is for that same reason that books pop out whenever you walk into not just a library, but a Barnes & Nobles, a consignment shop, a used bookstore and even the book sections at big-box stores.
It would also make your own shelves the subject of conversations when inviting company, whereas not so much with e-books which are confined to an e-reader.
Physical books also have the advantage of being stories in themselves, specifically of the people who may have previously owned them. Evidence of this could be found just behind the front cover, showing in pen ink the previous owner's name and what date they purchased it or whether it was a gift. There is no concept of a used e-book, rather it only functions as a cold, mechanical facsimile of literature.
What is also attracting about a physical book, is because of its financially and environmentally beneficial use. There might be an instance when a used book can be at a much lower price than the e-book version. You also do not need to consume electricity to read a physical book (unless you do not have natural sunlight and need a lamp), while you have to make sure the e-reader is charged enough.
I also like the convenience of grabbing a book from its shelf (or the floor because of how unorganized I am) and just reading it. With an e-reader, I have to fiddle on it until I can get the right book on the right page.
The tips of our fingers can pick up a lot more information than we expect, through our nervous systems that enter into our brains. This is what makes feeling the ink letters and turning the page more memorable than clicking the next page on an e-reader.
Of course, everybody has their personal preferences, but I merely present my case in why I choose my own. Although I do own e-books on my phone, almost all of what I read comes from my physical book collection.