Book doubt

There's no question that books still hold a special place. Imagine trying to get the blood pumping over the biggest seller of steel girders or marveling at the amount of floor space devoted to the sale of air compressors?

It has the been the long contention of tyrants that books can have a deleterious effect. Indeed it is the plot of one famous work Fahrenheit 451

And occasionally an obsession with books can be fatal though you would have to be very unlucky.

II

There are a couple of things to note about the ultimate bestsellers.  Yes, fantasy dominates and no doubt if you traveled further down the list you would find plenty of novels that fit that description. Those fellows who've dabbled in literary studies will bristle at each mention of the novel Don Quixote since it is actually a romance.
You really get your HECS money's worth when you find yourself in an exclusive club that doesn't then think of Barbara Cartland.  I don't blame people with only a passing interest in English as she is spoke to know the long works written in the seventeenth century and earlier, and what they were called.

So now your top ten novels must include The Lion, the Witch and the Wardrobe and let's add She by H. Rider Haggard for effect.

What other romances were there of note? I'm imagining Gargantua and Pantagruel
"Unlike the later form of the novel and like the chansons de geste, the genre of romance dealt with traditional themes. These were distinguished from earlier epics by heavy use of marvelous events, the elements of love, and the frequent use of a web of interwoven stories, rather than a simple plot unfolding about a main character. The earliest forms were invariably in verse, but the 15th century saw many in prose, often retelling the old, rhymed versions." [Huizinga, Johan (1996). The Autumn of the Middle Ages. Chicago: University of Chicago Press. p. 354.]