One of the best old comic fan sites on the web has to be Longbox Graveyard, maintained by Paul O'Connor. It's a celebration of Bronze Age (particularly Marvel) comics. O'Connor posts a major commentary once a week and hosts a regular podcast. What's apparent is his utter love of 70s comics. He explores issues in real detail and has some quite perceptive insights into what he reads.

Particularly recommended is episode 10 of the Longbox Graveyard podcast. It explores 70s Marvel science fiction titles (including Warlock and Guardians of the Galaxy) in a really engaging way. O'Connor persuasively argues that the success (or, rather, the lack of success) of science fiction titles is in the realisation of their background worlds. O'Connor explains his idea thoroughly - and I have to say I'm convinced by his argument.

Longbox Graveyard has a wealth of material that's well worth spending an hour or two checking out.