Lord of The Rings is definitely considered to have literary merit, and Watchmen is definitely getting there too. It honestly wouldn't surprise me if in a few generations kids will be learning about that comic in school[footnote]The sad thing is they'll probably hate it too, simply because they've been forced to read it and go over it endlessly along with a bunch of other uninterested children.[/footnote], it already has a ridiculously high standing in many circles.
Really though, anything can end up being considered a literary classic, as long as it's at least somewhat old. Even Shakespeare's plays were apparently considered pulpy at the time they were created, since they weren't Latin or Greek like "proper" plays.
Really though, anything can end up being considered a literary classic, as long as it's at least somewhat old. Even Shakespeare's plays were apparently considered pulpy at the time they were created, since they weren't Latin or Greek like "proper" plays.