Papers every complexity theorist should read I am starting my PhD this autumn and I am planning to work in complexity theory for my thesis.

I am compiling a list of important papers that every complexity theorist should know.

What papers would you suggest to a person like me? And please briefly explain why you think the paper is important.
Ryan William's Non-uniform ACC Circuit Lower Bounds and all the results cited therein. 

Not only is this a recent important result, it is a very well-written paper. Furthermore, the results the paper uses and cites cover a pretty good range of seminal complexity results. So if you trace through the references and read those as well - get to a point where you understand every part of the ACC lower bound from first principles - I would think that would be an excellent start to a graduate complexity education.