Always Watching blog has a neat post about the 10 Most Badass Geek in Film and TV. Now, I'd never thought I'd see the words "badass" and "geek" all in the same sentence (discounting the obvious "badass beats geek").
For example, here's MacGyver:
Secret agent Angus MacGyver (yes, his first name is Angus) is such a geeky badass, he's even got his own Wikipedia page dedicated to the 100+ problems he's solved in awesomely creative ways. This includes everything from defusing a highly advanced nuclear warhead with a paper clip to plugging a sulfuric acid leak with chocolate. And that's just in the first episode. Need more convincing of his geek-tastic badassery? Just check out that hairdo.
http://www.alwayswatching.org/features/10-most-badass-geeks-film-tv - Thanks David!