It seems that Guilty Crown consists of all the things that would make a great anime. From mechas to pretty girls to cool fight scenes. After a few episodes, you get a sense of what the overall plot is, and it reminds you of other great series that have come before like Code Geass.
Like Code Geass, this series involve a boy with powers. It has a multiple cute and well trained lady fighters. And of course, the mech suits. While everything seems nice on its own, so far through four episodes, all of the elements don't mesh well. When everything is put together, it seems a little generic. But that may be a different case once the story moves along and develops the characters more.
Animation is great, characters are cool, except the main character who is more whiny than anything else, and the central element is pretty standard for a great anime. Oh the central element? Yes, it's about a terrorist group battling the goverment to gain freedom, and this young high school boy has the power to pull different weapons out of different people depending on their personality to use in battle against evil.
The verdict on the series? Let's keep watching.