The last of the fiasco-genre movies I watched (at least for the sake of familiarizing myself with the genre -- other movies I watched are in the list, maybe, but that's not why I watched them) was Blood Simple. Of the three, A Simple Plan was my favorite, and Blood Simple my least favorite, with Lock, Stock, and Two Smoking Barrels falling squarely in the middle.
Mostly, it's because the story in Blood Simple didn't interest me at all. It's not just that I didn't care about the characters, or what happened to them. It's also that I really didn't find there to be much there even to be disinterested in. It felt like there was about 30 minutes of movie, and then an hour of moody camera angles. With everything so slow, and every character so miserable that you didn't care what happened to them, it seemed like the movie tried to overcome the ennui by making sure what happened to them was so, so, so awful that it somehow overcame the unconcern. But even when it got to its worst (those who've seen the movie might guess which scene I'm thinking of -- though I have two in mind) and my reaction was suitably (though mildly) horrified at the idea, I still didn't quite care.
I can't blame the acting or production or even the direction (apart from the incredibly slow pace). It really comes down to that there was nothing about the story to intrigue me at all, and there wasn't anything else.
But since I wasn't watching it for enjoyment but instead to understand the fiasco genre, I think it served that purpose.