Interesting idea, because I've been working in IT for 15 years and the cute female nerds I briefly met at college never reappeared in the workplace. Where do they go?
Have you heard of a UK sitcom called Peep Show? It's a clever idea as it follows two flatmates and it's always strictly from one of their points of view. I can't think they've ever been in one shot together. Plenty of monologues and very funny. In one series, Mark meets a girl who does tech support for their office. Very nerdy, even carries her own block of cheese with her!
But, Karsten, I'm not sure you can include Willow. In a show about fit women, it was bound to be a fit woman who got the geek role. Could have been Xander, but that would have been way to obvious!