I haven't noticed many TV sheroes being posted, so I'll take a stab:

Veronica Mars: Snappy, self-reliant, hard-boiled high schooler? I'm there. Granted, she can make some pretty bad decisions for herself (following strange guys into bars, falling for someone who was threatening her half a season before) but I like that she's human in that way. It makes for a rounded character. Plus, I love the portrayal of her relationship with her father.

And what about all the women from Serenity and Firefly? Another Joss Whedon opus, which is good, because he's all about the strong female roles. Each of them are fierce and independent for different (and unusual reasons): Zoe, the militant who is also married; Kaylee the mechanical genius; Inara, the concubine type who doesn't take crap for her profession and fights better than half the guys on the ship and River, who seems sweet and loopy, but cares deeply for her brother and crew, and kicks serious butt when the time calls for it. They're all really unique and special, and I wish the series had had the time to develop everyone, because it was just too cool and inspiring.

It does spawn off an interesting side note, though. Joss Whedon is notoriously pro-woman, and writes strong female characters - how many of our favourite sheroes so far are born of the male writer/director? (Tarantino, Whedon, Miyazaki, etc.)