Ender's Shadow was good as well, really any of the books in the Ender series. I have not read any of Orson's other works.
I will have to check out the Commonwealth Saga.
Commonwealth Saga is Space Capitalism
Culture Series is Fully Automated luxury gay space communism, thats the way Banks himself described it lol.
They both posit very interesting philosophical questions and scenarios for the future direction of humanity and the purpose people will have when no one really has to work anymore.