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.
The "puny human" scene where the Hulk bursts out of Bruce's mirror made for a great teaser trailer, and makes sense as broad symbolism of the conflict between Bruce's fears and psychoses (the Hulk). It was included in the movie... in the middle of a fall off a fighter plane. Bruce was dreaming it, but it makes no sense in the context of the fighter jet attack.
Betty tells Bruce about a nightmare she had. It begins with a memory of her as a little girl eating ice cream with her father, only for him to have to leave her there when he receives an alarm from his base. Betty panics from being left alone, and a bright green mushroom cloud booms behind her. Then adult Bruce shows up and strangles her. The end.
A case of It Makes Sense in Context; Betty is actually remembering what happened the day Bruce's father killed his mother, up until her subconscious goes Freudian.
Broken Base: The arguments about which is better: This or The Incredible Hulk. Seriously, there are civil wars that have been less heated.
Critical Dissonance: It's very interesting to view this in comparison to the 2008 The Incredible Hulk in how it was received. This film is generally considered long and boring by regular moviegoers, but the critics tended to like it for its focus on character pieces and big ideas over the violence and CGI. The '08 film had a greater amount of fans agreeing with the critics, but some lamented how the new film took away the big ideas to put in more action and typical comics stuff. Besides all of that information, both films did about the same at the box office.
Ensemble Darkhorse: Sam Elliot's portrayal of General Ross was extremely well received by the fans.
Moral Event Horizon: David Banner using Bruce as his personal guinea pig for his experiments, and after Ross throws him off the project, triggering a nuclear explosion of the military lab (and it's strongly implied the explosion took many lives, and caused the entire town to be abandoned), and murdering his wife in front of Bruce.
Special Effects Failure: The Hulk himself is accused of being this because of his skin color. The Hulk Dogs on the other hand never had a chance. The 2008 film addressed the skin color problem. But as consequence, made him shiny in some shots.
Uncanny Valley: Hulk's green CGI skin was completely opaque, which unsettled a lot of people.
Vindicated by History: A unique example. Hulk's still got a bad rating in IMDB (usually only around 6), but many hardcore comic book fans and amateur movie critics has started to praising the movie's good quality aside the score (such as the movie's analogy on Hulk's virtually unlimited strength in the last action scene, where Bruce defeated his father by released a very large ammount of gamma energy, turned him into a large bubble). The movement has been there since at least 2006
Wangst: One of the film's criticisms was that there was too much of this and not enough smashing.
The ending also involves the the four classical elements, earth, air, fire, water. The absorbing man transforms into an electrical being and fights the Hulk in the form of a thunderstorm (air), then melds with a mountain (earth), and then turns into a watery being in the nearby lake (water). The Hulk, as a source of energy and heat in that scene, with a green fiery aura at one point, would identify with fire.