After seeing it on the list in this thread, I decided to read Annihilation, and I just finished it. As others said it's weird (I like weird, so it's one of the reasons I wanted to read it). The writing style really reminded me of H.P. Lovecraft, which is to say it's a bit stilted. I'm glad I read it - it's an interesting world and the story is told in an interesting way - but it's not a book I'll recommend to a lot of my friends. Some of them, maybe.
I read it because someone at work recommended it to me but I didn't find it very compelling. I think I read all of the books in the Southern Reach trilogy. It didn't strike me as being anything special, just average sci-fi.
I'm getting to be pretty much a hermit, and didn't realize there's a movie of it until someone mentioned it in that other thread. Didn't sound like a must-see.
I might read the next in the series, but it's way down on the list.
The movie is one of my favorite sci-fi movies ever! It's nothing like the book except for the premise, and way better than the book. I can't recommend it enough!
I hadn't known there was a movie until recently, and I haven't seen it, so I can't tell you how it compares. Some comments on this thread talk about it.