From Wikipedia:
Konata is, more by default than anything else, the "leader" and the shortest of the main characters. Nicknamed "Kona-chan" (こなちゃん?) by Tsukasa, she is an eccentric but friendly and outgoing girl, with a mischievous yet good-natured sense of humor. She can be smart, but she hates studying, thus her grades are a bit uneasy. However, she is an expert at pulling "all-nighters". In contrast to her studying habits, she loves video games, to the extent that she can compete against Kagami Hiiragi on trivia-based games. In addition, she loves anime, which is also due to her father, Sōjirō Izumi's influence, along with the games. Her father buys adult games for himself, so she is able to play and enjoy them. In fact, when she became eighteen, Konata was overjoyed, since she could now go buy and play adult games legally. In the anime, Konata constantly refers to or parodies several popular games, anime, and manga (much to the annoyance of Kagami).
In the series, characteristically poses/face pulls a lot:
http://reira.zuiken.net/wp-content/u...04/konata1.jpg
http://blog.jpopdb.org/media/nendo_konata.jpg
http://quakeulf.suxos.org/gallery/al...ree/konata.jpg
http://gallery.fanserviceftw.com/_im...0wallpaper.png
Bias says she's an Alpha SF, just because I'm tired of my club/quadra not appearing in media