The Simpsons' Jeff Albertson, a.k.a. Comic Book Guy, is such a popular character mostly because there's a Jeff Albertson in every town in America. One only has to visit a convention dealer's room to see a surly behemoth letting his misanthropy get in the way of what ironically is a frivolous entertianment. CBG is also a renaissance nerd, as he can pontificate about baseball cards as well as he can discuss Dungeons & Dragons, and do both speaking Klingonese -- although 99% of his conversation will be about how these things suck and used to be much, much better. Truly, he is a nerd for all seasons.

http://www.toplessrobot.com/2009/06/pop_cultures_10_greatest_nerds.php

What about Urkel?