My two favoritos are C.C. from Code Geass and Lucy/Nyu/Kaede from Elfen Lied but since I am currently watching the segundo season of Jigoku Shoujo, I feel like posting my third favorite, Ai Enma.
What animê is Squid Girl from please tell me so that i can watch this animê on youtube than i will tell you if i like it or not than i will goin a fã club of this anime.
Both seasons of Squid Girl (that's the show's name too) are on Crunchyroll. If you don't mind watching a few commercials, you'd be helping the producers of the shows por watching it there. The first season dub is also on Netflix if you have that. link