GIMP, Wacom Tablet and Fractal Explorer (not Apophysis like I wrote earlier). Robin Sena from the anime Witch Hunter Robin
Jaime wanted me to upload this, so here it is. I'm not really happy with the end result because the lines are too shaky and the image looks too similar to the screenshot and I'm not sure what happened with some parts of her hair. I also don't really like this style of shading, but I'm not that good with a tablet so I went for simplicity. I probably won't keep this one up too long in the gallery.
Original Sketch: [link]
Original Screenshot: [link]