Halloween is the only religious holiday I willingly participate in. It is a special day, and a lot of fun. Also, Halloween is a nerd's Christmas. It is the one day that cosplay is 100% acceptable. Since Halloween revolves around all things spooky, it relates to some of the nerdlier aspects of film and television. So, without further ado, here is the special Halloween Nerd Girls of Note.
I will forgo the normal info-block here. This is, of course, Elvira: Mistress of the Dark. No Halloween would be complete without her. Portrayed by Cassandra Petersen, who is possibly the most perfect nerd girl in existence; she has had her own comic books (see Jamdin's blog for Claypool, Marvel, and DC comics), she has an encyclopedic knowledge of bad horror movies, has her own pinball machine and PC games, she is dead sexy still at age 57, and for her it is not cosplay—it is coslife. As if that were not enough, she was a Vegas showgirl, is in the Guinness Book of World Records which cites her as the youngest showgirl in Las Vegas history, she dated Elvis Presley, she slept with Tom Jones, and is on a Tom Waits album cover (as the stripper on Small Change (1976).
If you don't remember Elvira's Movie Macabre, you didn't see it. It was very much the forerunner to Mystery Science Theater 3000. Elvira would introduce some horrible film, then break in at certain points, or around commercials to crack on the film. Her jokes were always double-entendre, breast jokes, or wordplay, such as [paraphrase] "now back to The Head with Two Things. I mean, The Thing with Two Heads!" You can see episodes of Movie Macabre at FanCast here.
Cassandra Petersen is an animal rights activist and vegetarian who uses her Elvira celebrity to support PETA and other animal rights organizations. She appears at many events, and appears on PETA's website in a Halloween segment educating people about animal products in some candies called Elvira's Halloween Treats.
Next we have model turned nerdo-centric actress, Mila Jovovich. She has done a lot for the film watching nerd community. Not all her films are great, but they are typically at least B+ affairs.
I would say her nerd-film breakout role was The Fifth Element (1997). This film straddled the A-list/B-list divide, providing great action and genre specific elements, then had high caliber (or at least visibilty) actors paired with genre heroes. Gary Oldham and Bruce Willis next to 'Tiny' Lister and Brion James.
She appeared as Katinka in Zoolander (2001), playing a ridiculously bitchy and violent Eastern Block model. She then went on to star as Alice in the Resident Evil films, as well as staring in Ultraviolet (2006).
Sybil Danning is another nerd-movie superstar. She's run the gammut; commando/espionage, sword & sandal, sci-fi, sexploitation, women in prison, and for Halloween, the horror movie, Howling II: ...Your Sister Is a Werewolf (1985) as Stirba, the werewolf queen. Most recently, Ms Danning appeared as Gretchen Krupp in the Grindhouse fake trailer for Werewolf Women of the SS (by Rob Zombie), and as Nurse Wynn in the remake of Halloween (also by Zombie).