From the Bureau of Ruben Has Been Blogging Too Much About K-On we have this poll by the Otaku no Podcast folks over who people's favourite characters are.

The results are encouraging, it seems I'm the only one who has voted for Mugi-chan, which means she's mine by default :3! Of course I'm also dismayed at the same time, as this implies she didn't receive any votes before I came along, when the others did! Fight Mugi, fight!