While all of the stories in this collection are good, there is one that for me is a standout story of the robot SF genre, namely The Velvet Glove, published in 1956. Set in context, that's just a couple of years after Asimov's "The Caves of Steel". Harrison takes the next step, writing the story from the point of view of its robot protagonist (Jon Venex), but his target is surely the racism of the time, and his question is clearly "What is a man?".
It's not only a political statement, but a (short) crime thriller in its own right, and one in which the robotic nature of the protagonist is central to the plot. For many years, for me at least, this was the story against which all other robot stories were judged.
To be fair, the other stories are very good as well (though the robots are mostly more robotic, or more computer-like). It's just that none of them has stayed with me quite as enduringly as Jon Venex.