Kotonoha from School Days. Obsessive love triumphs. Kurumi from Date A Live. She is pretty seductive and has a alluring seiyuu. Shion from When They Cry. Again, obsessive love is the best.
Yuno of course. Classic yandere. And holy crap, Rena, Lucy, and Flandre are not yanderes. 2 main qualifications of yanderes: crazy and in love. Rena's not in love. Lucy's not crazy. Flandre's neither (maybe a bit crazy..). Rena isn't that crazy either, just superbly amazing at swinging a hatchet. But haven't read either the Higurashi or Elfen Lied manga so, I'm judging by the anime. Fan culture does not count, sorry Flan-chan.