I tend to place importance on consistency and prolificity, those are to me the key things that make you the best. Anyone can have a streak or put a run together and beat a few respectable heads. Those who've consistently performed at the highest level over a long period of time, and more so over the span of many websites, tend to be highest on my list.
@
CopyPat seems to be the exception in my top 10 here, but I think seeing him missed off Certain's list all together made me want to give him his due props. If I worked further down the list to a Top 25 or even 50, he would probably be replaced for that reason alone.