2. Willow - Buffy the Vampire Slayer
If Willow was declared the Nerd Queen of the Universe, I don't think you'd hear objections from anyone. At the beginning of the series, she's a bookish nerd with an adorably painful crush on her best friend Xander. She falls into the role of Research Guy very quickly, and is always up for a little study session in the library (in fact, she's the only one who seems positively gleeful at the idea). As she matures, she comes out of her shell, but never loses her geek cred. I love the enthusiasm she throws at everything educational -- going to Career Day, taking the SATs, choosing a college, picking her courses, even going to buy books. While all of her other friends are blasé or openly terrified by this stuff, she basks in it. Willow is just a girl who loves learning, and it's probably the cutest thing in the world.