The semi-recent 50 volume set of Central Committee documents (pre-Cultural Revolution) comes to mind: 中央档案馆 and 中共中央文献研究室, ed., 《中共中央文件选集, 1949年10月-1966年5月》, 50 vols. (Beijing: Renmin chubanshe, 2013).
A number of municipalities and provinces also have similar types of document collections. Beijing, for instance: 《北京市重要文献选编》, covering 1948-1965.
I often use collections and neibu/books published under the 《中共重要历史文献资料汇编》 series by the 中文出版物服务中心 in Los Angeles. However, I know nothing about this organization--does anyone have any insights?