The Caves of Steel

Caves of Steel, Forever War, Childhood’s End

No, most (non-pedantic) Asimov fans refer to the first three books (F, F&E, SF - which yes are technically collections of short stories glued together as one) as "the Foundation Trilogy". I do recommend reading the Foundation's Edge and Foundation and Earth, they're worthy sequels to the "trilogy". The Robot novels are also a top read and tie in with the later Foundation books in a satisfying way: - The Caves of Steel - The Naked Sun - The Robots of Dawn - Robots and Empire

Isaac Asimov's robot series (start with "I, Robot" and "The Caves of Steel") is good, as is his Foundation series. Ender's Game is also good; I've heard other people complain about the other novels in that universe (Speaker for the Dead and sequels, Ender's Shadow and sequels), but I liked them fine. Cryptonomicon is rich, fascinating, and entertaining. Dune is rich and pretty fascinating. Heinlein's "Stranger in a Strange Land" and "Time Enough for Love" are somewhat scandalous, but I thoroughly enjoyed them. Outside science fiction: P.G. Wodehouse's Jeeves and Wooster novels, as well as what of his other books I've read, are hilarious and brilliant; I would suggest "Right Ho, Jeeves" as a starting point.

There's a large volume that contains all of Arthur C. Clarke's science fiction short stories. They're great because they are indeed short, and while not all of them are good, a number of them fill me with the same sort of wonder I get from reading the first Foundation book. If you're on an Asimov kick, The Caves of Steel is also pretty good, and has a Foundation-style twist at the end.