Into nice boats? Like your love to be cute AND psycho? This is the place for you. We're chaotic neutral and have no real alliances, so everyone who enjoys our adorable little yanderes can join~
If Lucy counts she's definitely my #1 favorite(I'd say she is Yandere, but that's a secondary characteristic compared to her plain ol' homicidal characteristics). If not, probably Yuno Gasai. I haven't seen the new anime, but I've read the majority of the manga.
I think you can definitely get too crazy, but as long as she will not try to kill me (a surprisingly difficult request sometimes) there is really no problem as long as they are cute.
Are you into the classic UR: EXAMPLES such as Sekai or Kotonoha from School Days, or are you into a more new and fresh variant?
Discuss it here.
My favorite is Lucy from Elfen Lied, she's sort of a UR thing, but, eh, she's my yandere of choice.