Some time ago I read a comic series (the name of which I'm not going to openly admit to) about the misadventures of a person in a distant future dystopia... or three, or five.  Each issue explored a slightly more altered interpretation of “human”, and in each issue the line became more and more blurred as the complexity of intelligence and capability of introspection increased.
The humanoid robots were easy: they weren't human. Simply having human shape and speech and an intelligence isn't enough. Aside from the metaphysical questions of intelligence and free will, that's still not a human entity. Classic robots, borrowed from an earlier time in science fiction where the mind was the key to humanity.

The dualistic, dueling AI pair blurred the lines. While one claimed to be human, and believed it was human, it had no body and a Self that was an amalgamation of memories, data, personalities and programming. The sympathies of the main character were initially swung by its “humanity”, but as events progressed, it became clear that neither AI thought in human ways despite one believing it was human. The gulf between the perspectives, motivations, inner thoughts, and fundamental mental processes of the main character and the AIs became more apparent and more ominous. The assumption that personality and emotion created humanity was destroyed.

As the series progressed, variations on the theme of “what is human?” became more complex. People's minds being moved into machines, conflicting and merging with the innate firmware or bios of the machine to create an ego/id that is both human and not; is this person still who they were, if their subconscious is now something different? Clones, programmed personalities, and alien mimicry all get touched on. Eventually, in a far and distant time, a race of sentient machines with individual personalities and free will spend eons trying to “reinvent” humanity and inadvertently “fail”; they create a species of perfect human genetic and mental copies who don't think they're human because they were created by machines. In the end, the “last human” turned out to be not human at all, and somewhere in the intervening time we missed when that happened. Now the question is “what is More Human, when there are no original humans to compare to? And what are we actually comparing?” in an environment where machines are, basically, human beings with metal and plastic bodies.
Each aspect of human existence, from genetics to intelligence, free will to emotions, identity to culture, was systematically questioned and a scenario created that straddled the line between human and “artificial”, or erased it entirely. In each case a challenge was made to the reader to pick exactly where in the gradient the line should be drawn, then in a few pages that line would be intentionally (and often tragically) blurred again. Oddly, or perhaps pointedly, this deep exploration was embedded in a prurient stew of sex, violence, and debasement; another facet of humanity rarely explored when the topic is artificial life and intelligence.