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