This is an interesting list. It’s missing some of the true great classics, like Frankenstein, and it has a number of unusual, less well known titles, but there’s a lot to like on it. There’s certainly a lot for people to disagree about, but it may well have your less often cited favorites, too. What do you think?
Flatland is worth reading, though admittedly it was decades ago that I read it (it may even have been high school). It’s clever; written in the late 1800s as a commentary on Victorian society and social classes. It’s from the POV of characters in a 2D universe, with forays about 1D and 3D universes. As a side note, it has a bit about a potential 4D universe, and it was written before Einstein’s relativity theory got people talking about higher dimensions. As I recall, it’s fairly short.