Much like a first kiss (or, in this case, an upside-down smooch) always seems the sweetest, the first “Spider-Man” movie remains the most purely enjoyable movie in the franchise. Indeed, there’s something not entirely unlike an air of innocence wafting about the entire enterprise as Tobey Maguire miraculously obtains, initially misuses, and ultimately focuses his superpowers, all the while pining for (and, briefly, winning) the seemingly impossible object of his desire, Kirsten Dunst’s girl-next-door Mary Jane Watson. A few diehard Marvel Comics fans quibbled about some evocations of artistic license — in the world according to director Sam Raimi and scripter David Koepp, Spidey’s web is natural fiber, not synthetic additive — but “Spider-Man” as whole proved largely faithful to its source material, particularly in its repeated questioning of whether the hero might ever catch a break. And that contributed generously to its huge success. The only unanswered question: Did Willem Dafoe actually intend to sound so much like Gilbert Gottfried while playing the villainous Green Goblin?