Scott Smith's wrote one of my favorite crime novels with A Simple Plan that released in 1993. Thirteen years later came his second book, The Ruins which instantly became one of my favorite horror novels. I've got my fingers crossed that sometime later this decade he'll write another one and maybe it'll turn out to be the greatest sci-fi epic I've ever read. 
 The concept here is dirt simple. Idiots go somewhere they shouldn't and bad shit happens. In this particular case four American college students, two boy-girl couples, are on vacation in Mexico where they meet several other tourists from all over the world. A German named Mathis tells them that his brother got smitten with a woman and followed her to an archaeological dig in the jungle, and that he needs to retrieve him before their flight home. The Americans and another Greek fellow decide to join him and set out on an impromptu adventure following a hand drawn map to a remote location. 
 A bunch of unprepared and ill-equipped tourists wander off into the jungle? What could possibly go wrong? 
 After they find themselves trapped on a hilltop by something that defies belief the young people endure thirst, hunger and injuries and have to consider extreme actions in order to survive. 
 The sub-title of this book could almost be A Series of Bad Decisions, and that's one of the aspects that made it unique for me. A lot of horror is based around punishing people for their actions. Frankenstein gets his monster for daring to try to change the natural order. Jason slaughters teenagers for acting like teenagers. In The Ruins there is no single moment of arrogance or failure of character to point out as the thing that bring about the situation. (Although there are plenty of small examples of rotten behavior that make it that much worse.) Rather it's just the sunny optimism that everything will be OK that puts these kids in a leaky canoe headed up that fabled Shit Creek with no paddles. 
 Smith does a great job of playing off the human nature of being in a bad spot and wondering how you got there only to have the sickening realization that you knew for a while that you heading into trouble, but you somehow talked yourself into staying the course it with the assumption that everything would work itself out. 
 The characters themselves are a departure from what you get in most horror novels these days. Yeah, I know some people hated them, and they truly are a pack of insufferable dumb asses for a large part of the book. But I think what some readers really didn't like about them was that they did act the way most of us would in those circumstances. For example, Jeff tries to play the hero, and while you can empathize with his frustrations with the others he's also being a complete douche bag for not acknowledging the bigger picture. The others also act with varying amounts of denial and panic. 
 What's interesting is that there are no easy answers as to how they should be behaving. (Serious spoilers here.) (view spoiler)[Jeff's insistence on amputating Pablo's legs and trying to convince the others to eat the corpse of another illustrates that you can make a bad situation worse by trying to do the right thing. On the other hand, sitting around and drinking tequila is criminally irresponsible on the part of Amy, Eric and Stacy. (hide spoiler)] So there's this uncomfortable push-pull between the traditional concept of doing every single desperate thing you can think of to survive versus realizing that you're fucked and just giving up. That's the grey zone where this book operates and part of what I found so compelling about it. 
 I've seen some complaints about the nature of the threat, and I'm not sure if that's still considered a spoiler or not so I'm throwing it under a tag. However, I'm only discussing what they're facing while not giving up any plot details. (view spoiler)[ OK, so it's a plant, and I get why some are skeptical of the concept. The mystery probably didn't help that when it first came out because some people were expecting a chupacabra or jungle cannibals or something along those lines so that when the reveal came, the first reaction was "They're fighting a fucking plant?" I remember being surprised and wary the first time I read this, and the stuff about it being an intelligent and mimicking sounds did strike me as far-fetched. But is it really any more fantastic than vampires, zombies, werewolves or Texas chainsaw massacres? In the end, the insidious nature of the vines became another major plus of the book for me. (hide spoiler)] 
 So this one retains its high spot among my personal rankings after reading it a second time. It's not your typical horror tale, and it's a gruesome story that shows people behaving poorly in dire circumstances which makes it an uncomfortable read at times. But isn't that the point?