10 Classic. Nothing about this book strikes you wrong and everything about it strikes you right. Faults aren't even faults, but are either quirks instead or utter non-issues in the face of so much ****ing awesome.
Ex: Blue Beetle #24, Astonishing X-Men #23, Fray, Black Adam: The Dark Age, Annihilation
9 Awesome. The reason we read comics. Any faults are mere nitpicks and virtually negligible.
Ex: Infinite Crisis, Dr. Strange: The Oath, JLA: World War III, All-Star Superman, Rucka's Wonder Woman, Checkmate, Gotham Central.
8 Great. Books regularly hitting this stride are required pull-list material. Some faults, though they rarely detract from the reading experience in a notable way.
Ex: Green Lantern Corps, Morrison's New X-Men, Fallen Angel, Identity Crisis, 52, Young Avengers, Booster Gold, Nova
7 Good. A safe and reliably pleasant comic with memorable goodness. There are several avoidable faults that take away from the experience, but generally it's a solid cut above the rest.
Winick's early Green Arrow, The All-New Atom, Slott's She-Hulk, BKV's Runaways, New X-Men: Academy X, World War Hulk #1
6 Tolerable. Worth a read-through for some nice story or character moments, but a number of distractingly weighty faults are beginning to take their toll. Proceed with caution.
Ex: Winick's middle Green Arrow, Civil War, Sinestro Corps War, McKeever's Bird's of Prey, Avengers: The Initiative, The Trials of Shazam
5 Average. Anything good is countered with something equally bad. Any book with this score and below doesn't deserve your money for any reason whatsoever.
Ex: New Avengers, Mighty Avengers, McKeever's Teen Titans, Millar's Ultimates, McDuffie/Burnett's Justice League of America, World War Hulk #5
4 Unacceptable. It's not that it doesn't have good things, it's just that the good things are incredibly hard to appreciate because crushing mistakes are being made here that could easily have been not made.
Ex: Winick's late Green Arrow, Craig/Yost's New X-Men, Kelly's Supergirl, Austen's Uncanny X-Men, Picoult's Wonder Woman
3 Bad. Very few things to recommend, if any, and a great deal of things going against it, including an abundance of poor characterization, poor story, poor dialogue/scripting, poor pacing, general pointlessness, or usually some combination of the above.
Ex: Avengers: Disassembled, House of M, X-Men: Deadly Genesis, JLA/JSA: The Lightning Saga, Beechen's Teen Titans, Spider-Man: The Other, Ultimate Nightmare/Extinction/whatever
2 Horrible. There's no excuse for the things that have transpired here; every single person involved should have known better. Still, you can at least sort of see where they tried to not suck so hard, and probably didn't mean to create something so offensively bad.
Ex: Countdown to Final Crisis, Spider-Man: Sins Past, Ultimate War, Loeb's Supergirl, New Avengers #20, Civil War: The Return
1 Trash. Comical in its ineptitude, as in it'd be funny if it weren't so sad. It's like the creators intentionally set out to make a ludicrously ****** product and to piss off as many people as they possibly can. Doomed to become running gags in future comics and in-jokes on the internet.
Ex: Civil War: Frontline #11, Spider-Man: One More Day
0 The Anti-Life Equation. The Beast of Judgment. It is the dark at the end of everything. The end of universes, gods, worlds...of everything.
Ex: Amazons Attack.