A good movie based on a comic book is rare, and a great one even rarer. Stories of larger than life heroes fighting against villains on epic scales is the keystone to a great adventure tale in any medium, but being able to adapt a thrilling comic into an equally thrilling movie has proven to be nearly impossible time and time again.

'Spider-Man 2' is thankfully the exception, not the rule. Not only is this movie an excellent testament to a great superhero, it's also an improvement over the original film, which is quite a feat given how good that movie was.

Being a superhero is beginning to take its toll on young Peter Parker (Tobey Maguire). Taking time out of his busy life to fight crime is costing him his relationships with love interest Mary Jane Watson (Kirsten Dunst) and best friend Harry Osborn (James Franco). His academic and professional lives are beginning to suffer as well, leaving Parker to wonder if he even needs to be Spider-Man anymore.

At the same time, Dr. Otto Octavius (Alfred Molina) is planning on unveiling a new form of energy fusion with the financial help of Osborn. He has even constructed an elaborate device to wear on his back with long tentacles attached to it to help him manipulate the machine necessary to operate the fusion device. However, when an experiment goes terribly wrong, the device becomes fused to Octavius, who is soon driven mad.

Dubbed 'Doctor Octopus' by the tabloid paper Parker shoots freelance photos for, Octavius insanely goes on a crime spree to raise funds for another experiment. Parker is forced to make a choice -- does he live out his own personal dreams, or must he sacrifice his desires and live up to the responsibilities that come with his power.

The fact that 'Spider-Man 2' plays with the price it costs to be a hero is certainly what makes it so interesting. Not since the original 'Superman' movie has a superhero film series invested so much into developing the life of the normal, alter-ego. Peter Parker is clearly a real character, not just a liability that gets in the way of the Spider-Man action.

The movie has some awesome set pieces as well, including a lengthy battle between Spider-Man and Doc Ock that has them fighting over skyscrapers, bridges and eventually an elevated train. It's a fight every comic book fan dreams of, over-the-top, brutal, and full of nasty surprises.

Director Sam Raimi manages to invoke his inner demolition derby again, giving us the same insane camera work that he used to bring 'Evil Dead II' and 'Darkman' to life, only this time he's given more room to play. Raimi manages to pull off a miracle once again, making a movie that is completely his within the studio system, without compromising the integrity of the characters or disappointing fans.

Once again, Maguire gives a heartfelt performance as both Parker and the wall crawler. He makes Parker clumsy, goofy, intelligent and heartbroken, and Spider-Man tough, determined and brave, pulling off both sides of the personality flawlessly.

Dunst is amiable as Mary Jane Watson, but not really distinguished. She does give MJ a certain flair, and doesn't do anything to sabotage the character, but her performance never comes off as anything other than adequate.

Series newcomer Molina on the other hand is at his scenery chewing best, doing his best villain take since playing Snidely Whiplash in 'Dudley Do-Right.' He makes Octavius deranged but motivated by a good cause, which gives his evil a certain added punch.

Smaller parts do not go unappreciated, either. J. K. Simmons is funny returning as J. Jonah Jameson, the anti-Spider-Man newspaper editor who serves as the movie's comedy relief. Longtime Raimi collaborator Bruce Campbell also has humorous cameo as a theater usher on a power trip.

Special effects are of course top notch again, especially each of Doc Ock's tentacles, which have a distinct snakelike appearance. The webslinging scenes are still a joy to watch on the big screen, as are the otherworldly battles.

If 'Spider-Man 2' has any hindrances, its due to the sometimes hokey script and other unnecessary extras. The story turns maudlin whenever someone goes off on a tangent about the importance of responsibility or about how necessary a hero is needed. A funny scene involving Spider-Man in an elevator goes on a tad too long, and a wedding subplot is thrown in seemingly randomly and resolved just as quickly.

Still, 'Spider-Man 2' remains the best superhero sequel since 'Batman Returns,' and perhaps the second best of all time behind 'Superman 2.' It's rare to see a summer blockbuster get so much right, especially this summer which so far has been high on spectacle and low on humanity.

Heroism remains a needed ingredient in this Post 9/11 world. You can't help but notice the strong verve on screen as New Yorkers cheer on Spider-Man as he swings into battle. His is a struggle that is powerful because, as we know, under his costume he is still just a human being. If that doesn't resonate with audiences, I don't know what will.

9 out of 10 stars. This is everything a good comic book movie should be.