When I first started this thread, it was very tight at the top between four or five people, but after winning several contests in a row where there weren't many participants, I ended up being in the lead by a ridiculous margin (which is partly why I've only entered a handful of contests over the last couple of years; the last thing I want is for this thread to end up looking like some self-congratulatory vanity-project).
With this in mind, I've been working for a while to implement the averaging system that I originally ruled out for being too much effort. It's taken a while, especially tracking down all the entries from users who never signed up to the new site, but I've finally managed to include a set of statistics that show the average number of points each user has scored in each contest they've entered. These figures are now included alongside the regular list, with the leaders marked in good old traditional gold, silver and bronze.
Under this system (and discounting Nepathian, who never joined the new site) the current three leaders are Ildorf, Joker, and Lefiou. And I've got quite a way to go to catch up with them.