Day of the Triffids

The Day of the Triffids by John Wyndham was published in 1951, and is a story of how earth is invaded by an alien species called "Triffids," which are a man-sized, stinging, sentient, and mobile carnivorous plants.  It rips into the action and suspense right from the get-go, and doesn't let up until the end.  It kind of reminds me of "The Walking Dead" t.v. series, in that it's not really about the monsters, but about what people will do to survive desperate circumstances, and how people retain their humanity when there is nothing left, in an end of the world scenario.  Survivalist fiction.  The writing is great, the invasion plausible, the characters are well written; it's 190 pages of high octane thriller: great stuff!