This and Anna Karenina
are as close as I know to perfect. The only thing that holds Frankenstein
back is the writing style; at times you're reminded that Shelley was only 18 when she wrote it. The plot and pacing are perfect, and the scenes are terrific - particularly the exquisite first bit of the monster's story - but there are sometimes some minor rough patches in the sentences.
It's a warning, of course, about creating things we don't understand. Everyone knows that. What I'm interested by, though, and where I think some people misinterpret Frankenstein,
is that Frankenstein's monster isn't a flawed creation. Some people think the warning is that we overreach and create...well, monsters, right? But Frankenstein's creation is instinctively good. He's smart, rational and kind, until he's irrevocably alienated. It's not in the creation that Frankenstein fails; it's in the raising of it.
So if Shelley is warning us against playing God, it's not because she thinks we can't create something wonderful. It's that she doesn't trust us to know what to do with it.