I sometimes joke that Isaac Asimov is my intellectual father: although that's not that far from the truth. His essays, pro-reason and pro-science, had a huge influence upon me growing up. He's probably best known for his science fiction novels, but I think his best fiction by far is to be found in his short stories. There are 15 short stories here in this 1957 anthology. Below I name my three favorites:
1) "The Dead Past" - This is my favorite Asimov story, not just of the collection, but of any I've read. It might very well have been the first Asimov, maybe even the first work of science fiction, I ever read, and it's amazing, because it forever shifted my perception of the meaning of time. And more than that, it's psychologically penetrating and emotionally moving in ways Asimov rarely managed.
2) "The Fun They Had" - The irony in this light-hearted story of computer-schooled children is smile-worthy. One of Asimov's most anthologized stories.
3) "Dreaming is a Private Thing" - This is something of an allegory for creative writing in general, but it's one story that really stayed with me, that I recognized just from the title, and even had imagery so vivid and memorable I immediately recognized it.
I'd probably recommend Isaac Asimov: The Complete Stories, Volume One as an introduction to Asimov's fiction over this one--that book includes the content of Earth is Enough but this book is definitely full of memorable classics. Some details in the stories are dated, certainly, especially in social matters. Asimov considered himself a feminist and he created one of the most brilliant female characters in science fiction in robotologist Susan Calvin (featured in "Satisfaction Guaranteed"). But in these stories that men make all the important decisions, both at work and home, is taken for granted. Central planning--done by computers, of course--is also taken for granted as the wave of the future. But what struck me nevertheless is how well these stories held up, and how memorable they are. With many here I only had to see the title to remember the story--even though it had been decades. With others it didn't take many pages for them to come back to me. The ideas are clever, the twists unforgettable.