This is the perfect end to the trilogy and a fantastic film!
Ever scene works. The film understands Peter Parker perfectly, and works so well due to the relationship between Peter and Mary Jane. 
The film, seems to derive hate, for the reason of “To many villains” 
And honestly, There isn’t to many villains. There’s the right amount. 
Looking back at the films, within the trilogy and viewing them as the context for the villains within Spiderman 3 shows just why it’s the right amount. 
Sandman - Uncle Bens killler, and culmination of Peter “revenge arc” finally coming to terms with what happened to his uncle, his role within that, and the forgiveness he will always desire. Being able to forgive Sandman allows him to forgive himself, which plays a crucial part within Spider-Man’s  character.
Hobgoblin - Peter’s handling of his relationships, and the actions of his first outing as Spider-Man. And the cost of lies between friends. Also, impotent to Peter’s forgiveness arc. 
Venom - His built up ego, raging out of him. A nerd like Peter it was bound to build up, when given the powers he Gained. 
A perfect culmination.
The dance scene. Peter is a nerd. The suit boost his ego tenfold. What does a nerd like Peter think is “cool” that! Jazz! Showing off! It was an extension of something he thought he always wanted. What he thought was the cool thing. 
We see prior to the symbiotie taking hold of Peter that his ego, was already on the tipping point. Not think of Mary Janes feelings and only thinking of him self. His reaction to Sandman and Harry, through the trilogy we go from the bullied school kid, to confident and cocky, to learning forgiveness and the cost of being a hero to Spider-Man 
Sam Rammi did a fantastic job and made one of the best superhero trilogy’s of all time.