Created by 'God of Manga' Osamu Tezuka Astro- known in Japan as Mighty Atom- became the first iconic character in anime. Originally a sci-fi retelling of Pinocchio, the robot boy was created by a scientist to replace his dead son, but ends up being sold to a circus, before ultimately becoming a hero. Enduringly popular around the world, the character has returned many time since the original 60s incarnation. A Hollywood adaptation is currently in development.
BMO (Adventure Time)
What could be better than than a robot friend who you can also play retro videogames on? Not much that's for sure! BMO actually has many other uses, to the point that it is virtually a Swiss Army Knife of 'bots, but that's not it's most important function. BMO may be artificial, but to Finn and Jake it's part of the family.
Optimus Prime (Transformers)
According to Transformer mythology, the inhabitants of Cybertron, are not artificially created but actually life-forms who just happen to be robotic. So maybe we're bending the rules a little, but the leader of the Autobots obviously had to be on this list. Of all the Transformers characters, Optimus- who transforms into a truck- is easily the most iconic. If fans thought that Prime's demise in the 1986 was tragic, they hadn't seen anything yet. Some 20 years later he would face an even worse fate- appearing in those god-awful Michael Bay movies.
Go Nagai created Cutie Honey as his own spin on the Astro Boy. Honey is a android with similar origins to Astro, but is instead a fully grown (and because this was Nagai, frequently scantily-clad) woman. Honey fights for justice while gaining powers from various costumes she can summon out of thin air- in the process Nagai pioneered the 'nude transformation sequence' trope. After the original 1973 TV series, Honey has returned numerous times, with later TV Series, video series and a live-action movie directed by Evangelion's Hideaki Anno.
Mechazawa (Cromartie High School)
In this comedy anime that parodies the juvenile delinquent genre, there are some pretty.. unusual students. Alongside a Gorilla, and a Freddy Mercury lookalike named (naturally) Freddy, is Shinichi Mechazawa. The most popular member of the class is actually quite obviously a dustbin-like robot, but in one of the best running gags in the series- nobody seems to notice.
Nono (Ulysses 31)
No 80s or 90s cartoon was complete without the cute sidekick. In Ulysses 31's case, it was dinky red robot Nono, loyal companion of Ulysses' son Telemachus. Some people may tell you Nono was annoying.. and they may have a point, but he was a vital part of the series. He even gets his own solo section in the full length version of the show's excellent theme song.
No animated robo-list would be complete without Bender. Futurama has a whole array of robotic characters cropping up, but Bender Bending Rodríguez is the king of them all. This hard-drinking, gambling, foul-mouthed (as far as Network standards allow) robot is one of US animation's most loved characters- robotic or not. Despite his faults, his friendship with Fry was one of the defining aspects of the show. No other animated robot is fit to bite his shiny metal ass.