It all depends with what you're into. I'm a Animation student, so I like looking at other people's work, and learning about how they make the movie. The majority of them are worth picking up if you're into that. I would maybe leaf through one at a bookstore first, to see if it's your cup of tea. Then if you like it order it on Amazon 'cause it's like 30 bucks cheaper. I will say I like the Thor ones better, and I'm looking forward to the Guardians of the Galaxy a lot more than others coming out in the future. Simply because those movies have to create the world's around them much more when compared to say Iron Man. So the art in those ones are a lot more diverse and covers more. Whereas the Iron Man and Captain America books go heavily into the design of the costumes and gadgets, and not so much the layouts and background art. But they're definitely cool. And there are nice tidbits like Captain France says, the Iron Man 3 one has art for all the armors, and the Avengers has the official timeline in it.