While watching Batman (1989):
Mum (entering the room and seeing a newspaper on screen): Gotham Globe? Are you watching Superman? 
While watching Sin City (2005):
Dad (entering the room and listening to the dialogue): Mike Hammer?
But all this talk of comic nooks leads us on to the next post...
 But, oh so close. In the films, Gotham City is not as explictly New York as Metropolis is in Superman (1978), but both cities are so obviously New York that the mistake is entirely understandable. Or at least it would be if Mum ever actually watched these sort of films.
 This is a much more subtle mistake, because Sin City is indeed derivative of Mickey Spillane's Mike Hammer. Not that this is a bad thing; James Bond and Dirty Harry also owe much to Mike Hammer. Also Frank Miller has (apparently) drawn on other 40s crime-noir; it's just no-one remembers anyone but Mike hammer (including me, of course).