In this paper, we discuss the choice and use of benchmarks in each of five areas relevant to an assessment of the progress of EU electricity sector liberalisation. These areas are market design, market power, EU enlargement, regulation, and sustainability. Our aim is to discuss the most important benchmarks for each area, and to do so in the context of that area. Where a benchmark can be used as a signal that things are going well (or badly) we will discuss the values associated with a good (or bad) signal. This paper forms part of the final report of the EU funded Sustainable Energy Specific Support Assessment project (SESSA, see www.sessa.eu.com).