I placed my vote on Anezka. There was something about her attitude and her love for nature, as well as her general wiccan personality, that made me really like her from the start. Her speech at the end of the medallion quest, on what magic really is, won me over completely and I even developed something of a crush. To be honest, most of the other options would actually freak me out, were I to meet them; Anezka is the one female character I would actually want to know in real life, if I could, so that's why she's my 'favourite.'
"Magic, witcher, is the heart beating fast or the smell of wet, rotting wood. It upsets the underbelly and makes you weep and cry... It's the scythe that misses a field mouse nest, it's people coupling under the new moon until it hurts, it's blood spilled and sweet milk flowing."