First of all I will apologize for the mistakes I could make, I'm not a native speaker so it isn't always easy for me to speak in a foreign langage.

Story : 10/10

I know 10 isn't really objective but if I had to choose one manga for my entire life I think it is this one. I'm not going to explain the story, it isn't really useful. I just want to say that the author have developed perfectly the story, there isn't one mistake in it. There is a lot of suspense and it's not by accident that the author is called "the master of suspense". 20th Century Boys is passionating, I never have read à manga like this. It is not boring and the story doesn't stagnate.

Art : 8/10

Personally, when I saw for the first time the character design I was really doubtful. That's why I think an 8 is a good note. In fact, when you look more carefully you can notice the beauty of the art. There are so much details and the face of the characters approximates to the reality. I know this don't please to everybody but if the design stopped you just take time to look closely.

Character : 10/10

All the characters are interesting, they all have a story to tell. None is useless, none is a cliché of the traditional protagonists that you find everywhere else, and I think this is an important fact. You can easily identify you as one character, they are like anyone else, they are not superhumans, it could be you !You easily feel attached to each protagonist, even if you don't like one at first you discover something about him that show you that everybody is interessant and have a reason to be who he is. (I know that seems really optimist but it is real)

Overall : 10/10

I have already said it but you just can't be bored with this manga. For me, it is perfect, really. I have nothing bad to tell about it. If you hesitate, stop it now, read it ! If you like psychological thriller 20th Century Boys is perfect to you, you will like it, I promise ! I've never meet someone who don't like it.