“Shazam!”, indeed...those were good comics....
Silver Age and Bronze Age Marvels hold up very well too, I think. The thing is as the sixties dragged on and we entered the 1970s, a lot of the references get increasingly dated. It's unusual, though - a 1964 Spider-Man comic isn't as dated as a 1974 Spider-Man comic. Weird.
And people may be hard on Stan Lee - he hasn't been writing monthly Marvel Comics in ages.