I have been reading Barth for about five years now. My birthday present in 2010 was the Church Dogmatics, which at a special price of $100 may just have been the biggest bargain since 5p Woppa bars. (Church Dogmatics will now set you back $995, and Woppa bars no longer exist.)
The beauty of Barth's billion pages of theological reflection is that, due to his particular way of writing, you can just jump in to any volume at any point, and it will more or less make sense. He is always circling around the same object, looking at it from different angles, emphasising different parts of the whole. This method is captured in a little technique that Barth uses repeatedly. For example, he takes the commandment "Thou shalt love thy neighbour" and examines it using different emphases. So...
Thou shalt love thy NEIGHBOUR.
Thou shalt LOVE thy neighbour.
Thou SHALT love thy neighbour.
It is a simple method, homiletical in nature, and it is this simplicity that makes Barth's theology so forceful and so compelling. Barth is said to have summed up his theology with the children's song "Jesus loves me this I know, for the Bible tells me so." The volumes of Church Dogmatics can almost be understood as different emphases on this sentence.
JESUS love me this I know, for the Bible tells me so.
Jesus loves me this I know, for the BIBLE tells me so.
Jesus loves me this I KNOW, for the Bible tells me so.
Jesus loves ME this I know, for the Bible tells me so.
Jesus LOVES me this I know, for the Bible tells me so.