The Incredible Hulk #1
The first issue of Hulk is pretty interesting. It seems pretty clear that Marvel had no idea what to do with the character early on, as the Hulk's appearance and how Bruce Banner transforms into the Hulk changes pretty frequently in these early issues. Hulk is gray here, for example. Marvel isn't the only company that seems to have a hard time figuring out what to do with the Hulk, as neither of the last two movies seemed to know what direction to take the character in.
The level of atomic age paranoia in these early Marvel comics is pretty interesting, too. The Fantastic Four gain their powers by being bathed in cosmic rays. Bruce Banner gains his powers by being bathed in gamma rays. In both instances, the crucial event is caused by a science experiment gone wrong. Both Reed Richards and Banner are arrogant about their work before their respective accidents, and both have to live with the consequences of their arrogance (ie. Banner living with the Hulk, Richards with his guilty over turning Ben Grimm into The Thing).
The storytelling is uneven, but the early Marvel comics strike me as being cautionary tales, and Hulk #1 is an obvious example of this.