These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: The Happening
Anvilicious: There's plenty of this throughout the film. "You deserve this!"
John Leguizamo's character is the most sympathetic and the best acted in the bunch; of course, this means that he's one of the first to die. You'll probably be disappointed when you realize that the other characters aren't the Decoy Protagonist, because clearly this guy should have been the hero of this movie.
The bearded guy with the greenhouse who praises hotdogs is also pretty funny, and popular with many viewers. It doesn't help he pretty figured out what was going on before anyone else did.
Narm: The entire film. Particularly the lawnmower scene.
Paranoia Fuel: As stupid as the plot is, trees may seem a little freaky after this movie.
The old man in the house who shoots the two kids, Whether or not he's being affected by the plant toxins, imagine not being able to go to near houses to ask help for fear of being shot by anyone in them.
They Wasted a Perfectly Good Plot : Like many Shyamalan movies, it starts out really nice and eerie, and goes downhill once we get the (ridiculous) explanations. Unexplained mass suicides? Great, great. Caused by pissed-off plants? Not so great.
What The Hell Casting Agency: A milder version than usual but Mark Wahlberg as a science teacher is pretty oddball casting, and it's obvious that he feels uncomfortable in the part, especially at the beginning at the school.