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.
Magnificent Bastard: Sarone plays everyone like a fiddle in his quest for the snake. Eric Stoltz is the only person who manages to outsmart him even once.
Moral Event Horizon: In the second film, Dr Jack Byron establishes himself as a proper villain when he paralyzes one of his friends with a venomous spider (which leads to the guy getting eaten while immobilized), and steals the boats so the others are stranded to fend for themselves. When he runs into them again, he holds three hostages to make the fourth crawl dangerously close to the anaconda mating ball (aka dozens of males around an even bigger female) to get the orchid. So it's Laser-Guided Karma when he gets paralyzed by that same spider and falls right into the ball himself.
Narm Charm: Jon Voight's performance as Paul Sarone is absurdly over the top and its clear that whoever thought that casting Voight as a character with a thick ambiguously South American accent was a good idea was probably high. That said, in a film where the rest of the cast is so clearly apathetic about their performances its not hard to find yourself mesmerized by the pure and total hamminess of Voight's performance simply because unlike the rest of the cast he's actually trying. Winking at the heroes as if to say, "I told you so", when regurgitated by the snake is probably the high point of the film.
Anaconda: Between the weightless CGI models and the dull, dead-looking animatronics (though one could say that the CGI snakes are at least better than the animatronics), the anacondas are not inspiring fear. Especially silly is the short tussle between an anaconda and a jaguar, which looks like a wrestling match broke out at a taxidermist's office.
Hunt for the Blood Orchid may have had terrible CGI, but it doesn't compare to the sequels that followed it up.
So Bad, It's Good: Many viewers consider this film laughably stupid. Roger Ebert is one of the film's biggest supporters in this regard, often referring to it as "great trash".