Both Marvel and DC have done similar stories, albeit with markedly different spins on the concept between them. Marvel's was more the monsters coming together for their own cause (including what may have been the most original Punisher story arc ever), whereas DC's is more "monsters as government agents" kind of thing.
I've read those. And the BRPD comics. And the supernatural/war stuff with teams of monsters. Hell, I even read through the majority of the Godzilla comics - what I should have said was "I always thought a JLA / Avengers type group made up of mythical monsters would kick all kinds of ass if it wasn't written by a someone obsessed with the superhero comics he was aping, in a lame attempt at post-modernism which falls short of even basic storytelling." (superhero fanboys can feel free to throw things in my direction)
I'm not so annoyed at the amount of money I have wasted on superhero comics over the years, but I'm really, really aggravated at the utter contempt the majority of creators have for the intelligence of readers. Oh, and the pitiful use of amazing characters - go read
Eclipso - The Darkness Within (aside from the few issues with truly abysmal artwork) and you'll see what I mean on that front. They have one of the coolest horror characters in decades, and they throw out all logic in an attempt to gain as many readers as possible for their pissy little crossover.
*sigh*
There's a damn fine reason I try not to talk about superhero comics...