It's old, more of an essay, interesting enough.

I've read ten of the twenty one. The fact that it was so different than these types of lists tend to be, without being a bunch of fan fiction or whatever, is why I posted it. Just seemed like an interesting list. Of the ones I've read, I didn't dislike any of them, though there are some I certainly wouldn't have put on an all-time greats list myself.

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.