The Hulk first appeared in Journey Into Mystery #62--"I Was a Slave To the Living Hulk." He returned in #66. He was red, and had no relation to the Hulk we know. The Incredible Hulk,--"The strangest man of all time."-- first appeared in his own comic in 1961. Marvel still did not know if Fantastic Four was a hit, but Stan Lee and Jack Kirby wanted the monster to be the hero, so Doctor Bruce Banner was irradiated with gamma rays and became a monster. Originally, he turned only at night. He was gray at first, but quickly turned green, ostensibly because gray was a difficult colour to control on the page, but I wonder if it was not because he simply looked like a big black man and they didn't want to deal with that in the early Sixties. In 1963, he was a founding member of the Avengers. In 1971, a crossover story in Avengers #88 and The Incredible Hulk #140 was written by Harlan Ellison. Later, the Hulk joined a group called The Defenders: Hulk, Sub-Mariner, and Doctor Strange. No, I don't know what they were smoking at the story conference.
This movie is the Ang Lee version with Eric Bana as Bruce Banner--not to be confused with the Incredible Hulk movies which are part of the Avengers Saga. Jennifer Connelly plays his girlfriend Betty Ross, Sam Elliot her father, Nick Nolte his father. Nolte is riveting, but some have wondered why he's even in the movie. Lou Ferrigno and Stan Lee have small roles as security guards.
The basic plot is right out of the comic books: Bruce Banner is exposed to gamma rays. Thereafter, every time he feels angry he turns into a giant green creature of immense strength and power. In this version there is a longish back-story about how Bruce was predestined to react to gamma rays because his father exposed himself to radiation before the boy was conceived. This lengthens and slows down the movie quite a bit, though most of the story is introduced in a fast-paced montage of experimental research and the life of young Bruce Banner--from conception to adulthood in about 10 minutes. What we really want is to see the Hulk smash things and feel ourselves getting caught up in his tragedy. After all, the original idea for the comic was to blend Doctor Jekyll and Mister Hyde with Frankenstein. Marvel, like Shakespeare, only steals from the best.
Ang Lee tries to make the movie seem like a comic book with the use of split-screen panels, fast paced images and the driving music of Danny Elfman. The action scenes are big and impressive, with the Hulk smashing through walls, taking out tanks, helicopters, police-cars in the streets of San Francisco, and jets. No doubt producer Gale Anne Hurd had something to do with this. Thanks to the acting chops of Eric Bana and Jennifer Connelly, the emotion is there too. Some fans prefer this movie over the Incredible Hulk films, which often rely too much on flashy special effects at the expense of audience engagement with the tragic dilemma of Bruce Banner, until the later Avenger titles give us a Hulk with the face of Mark Ruffalo. I will say, though that the face of this Hulk has a kind of child-like look about it when he is coming down from a Hulk-out, which is quite effective.