Let me start right off and say "Spider-Man" is just about perfect, for a comic book movie. It is right up there with the "Superman" film starring Christopher Reeve and Tim Burton's "Batman". This film combines the fun and exciting action of the former with the dark and mysterious nature of the latter. The script is well written, witty instead of dumb, exciting instead of "we've already seen this before" dullness. The casting is top notch and the actors seem to know exactly how to play these characters.
The movie starts off with us getting to know Peter Parker played by Tobey Maguire. Peter is an academic nerd living with his aunt and uncle, and he often gets picked on by the bullies in his high school. He has a long time crush on Mary Jane but is too shy and reserved to ever do more than barely talk to her.
Then life changes. One day, on a field trip to a lab at Columbia University, Peter is bitten by an escaped, genetically altered spider. He soon discovers he has inherited spider-like powers such as the ability to climb walls, have amazing agility and strength, and even spin webs from his wrist. Peter decides to keep his abilities a secret and tries to figure out how best to use them.
At the same time, his best friend's father who is a scientist decides to experiment on himself and becomes a madman and the, soon-to-be, arch villain called the Green Goblin. The film is basically a three part story at this point: Peter learning how to use his new found abilities and powers, his quest for romance with Mary Jane, and his battle and confrontations with his mad rival The Green Goblin.
The film is bold and filled with wonderful colors just like out of a comic book. It is filled with many exhilarating action sequences with Spider-Man climbing up walls, jumping over rooftops, using his webs to swing from building-to-building, and, of course, fighting The Green Goblin. The CGI special effects are remarkable, making the audience truly feel and believe that Spider-Man is real and actually swinging between the skyscrapers in New York City. Much humor is added during the scenes where Peter is discovering his new powers and figuring out how to use them. The obsession and budding romance between Peter and Mary Jane adds a very real and smart romantic angle to the film as well.
While Willem Defoe is perfect as The Green Goblin and Kirsten Dunst is marvelous as the love interest, Mary Jane, Spider-Man's greatest strength is the acting of Tobey Maguire as the super-hero. He convinces us as both the nerdy Peter as well as the bulked-up Spider-Man. While much of the film is characterized by mesmerizing special effects, there is a real, fast paced story and smart dialogue. The director Sam Raimi deserves a lot of credit for putting this film together.
The only thing I would have done differently is to make a more interesting and exciting final confrontation and battle between Spider-Man and The Green Goblin, but that's a minor critique for this really fun, well-made, extremely profitable film.