Fargo
If I didn't know that Coen directed this, I'd have assumed that this is a Tarantino film. The style, the storytelling and the character's arc are really similar. Its a really good film. This has some unique quirkiness, where the Characters and the Events are memorable on the same level. McDormand did a really good job and her character is profound in this. And now I totally understand why Steve Buscemi was told to Shut the Fuck up a 178 times in Big Lebowski and I can't complain.
Edit after rewatch-
This is a masterful film. Loved this even more on my rewatch. I'm pretty much sure and can definitely state this, this is absolute Coen's best.