N° 1 on my list: the Metropolis (by lack of a real name called) MARIA robot!
Closely followed by my all time n°1 female heroine: NAOMI ARMITAGE - an third-generation android from Takuya Sato's Anime.
Tima from the Metoroporisu Anime would be nice.
Even if replicant's are a special case, I feel they fit perfectly in this thread. Where, if not here? I definitely want a RACHAEL from Blade Runner.
Also, her Korean counterpart Cyon form NATURAL CITY is an option.
Neon Genesis Evangelion's REI AYANMI which again is more some kind of construct than a cyborg or robot, I already have. Medicom was kind enough to make several versions of her.
Otherwise, there's the usual suspects, like TX 3, Major Kusanagi, ... I love androids, robots, cyborgs, ... so, there's quite a few I'd buy, if they are either design wise appealing, or have a strong presents in the movie/Anime/book.