How we cite our quotes: (Story title.paragraph)
Quote #1
"They're a cleaner better breed than we are." (Introduction.32)
This is Calvin's final opinion on robots, and we'll hear this a lot in the last two stories, "Evidence" and "The Evitable Conflict." Notice that we get this idea up front, in the very introduction. It's like Asimov doesn't want us to miss it: robots are fundamentally good.
Quote #2
You know that it is impossible for a robot to harm a human being; that long before enough can go wrong to alter that First Law, a robot would be completely inoperable. It's a mathematical impossibility. (Robbie.78)
Here we have some explanation as to why robots are better than people: because they're designed to be; or rather, because a robot couldn't work if it wasn't designed to be good.
Quote #3
"So Rule 3 has been strengthened—that was specifically mentioned, by the way, in the advance notices on the SPD models—so that his allergy to danger is unusually high." (Runaround.148)
Speedy is as moral as the other robots we meet. But his desire for self-preservation (Third Law) nearly gets Powell and Donovan killed. It's not that protecting himself is a bad thing to do, it's just that there's something of a conflict between his needs and his orders. Not to mention that this whole conflict comes about because Speedy doesn't understand the situation; if Powell and Donovan told him they need this selenium to live, he would've gotten it very quickly. No matter how moral he is, Speedy doesn't know everything.