Avengers, The (1963 series) #2

Hulk's last appearance as a regular member of the Avengers. The Space Phantom does return (next appearance: Avengers 106) where Hulk isn't involved.

No sooner does Hulk join the Avengers in #1 than he quits in #2. 1999's #1½ provided at least 1 adventure in between. In the current issue the Avengers already know that Ant-Man has become Giant-Man. #1½ includes them being clued in on this. For all but Iron Man the Official Index has nothing between #1½ and this one. For Giant-Man and Wasp they immediately follow Tales to Astonish #49 where Ant-Man first became Giant-Man. And also where they started using pills rather than gas to shrink and grow. Iron Man has Tales of Suspense #45-47 in between. But more significantly this issue is followed by ToS#48 where Iron Man will don the first of his more familiar red and gold armours. Rick Jones tells the Hulk (actually the Space Phantom) to return to his secret lab to turn back to Bruce Banner (actually Stan Lee mistakenly has him say Donald Blake). This indicates they're still using the machine from Hulk #6 to effect Hulk's transformations. Retconning will establish that Space Phantom isn't a random alien invader. Avengers Forever #8 will tell us that he is a servant of Immortus, hypnotised to believe his own cover story, sent to destabilise the Avengers. Immortus will also use Space Phantoms in #10 to impersonate mythical (or historical in the Marvel Universe) figures like Hercules. And so on.