It's puzzling to consider what landed any given story in The Arbor House Treasury of Science Fiction Masterpieces aside from Robert Silverberg liking it. If you're going to collect "masterpieces," it seems to me that the bar ought to be pretty high.
Philip José Farmer's "The Sliced-Crosswise Only-on-Tuesday World," from 1971, is one of those stories built around a punchline plot, summarizable in a single clause, that telegraphs its ending because it is all about its "shock" ending, which of course isn't a shock at all. To avoid problems related to overcrowding, individuals are awake and going about their business only one day each week; the rest of the days, they're in suspended animation, which people assigned to those other days do the necessary work. How any real work gets done is a mystery, but the story hinges on our protagonist falling in love with a woman assigned to a different day but who he can see in her sleep chamber, as she shares his house. As a result of his love, he wants to switch over to her day. His love is an adolescent thing, built on nothing but her looks, and the outcome of all this, even with a small twist tossed in, is obvious from the get-go. I have yet to read any Farmer fiction that I've liked, but I've only read a few things.
1958's "The Men Who Murdered Mohammed," by Alfred Bester, is a lark about time travel that's both entertaining and clever; unlike the Farmer tale, it does not telegraph its ending, though it certainly could have. Bester has fun with the idea: a man finds his wife in the arms of another man, so, genius that he is, he goes to the basement, slaps together a time machine, and goes back in history to remove her from his life. For some reason, this doesn't work, so he keeps heading back, knocking off various historical figures, both major and minor, in an attempt to, finally, see something happen in his present life. The conclusion is logical enough, but, more importantly, it's aesthetically and dramatically satisfying, given some elements that at first seem unrelated to the plot.
"The Man Who Lost the Sea," by Ted Sturgeon (and, with a glace back at the proceeding story, I should mention that there's even a third "The Man Who" story in the book), from 1959, is a bit of a slog at times, though there are, in retrospect, some clever touches. Written in a sometimes-effective, sometimes-strained literary style, the story keeps you guessing for quite a while as you follow the thoughts of a man lying, evidently in a space suit, on a beach. What's he doing there? Who's the little boy who keeps bothering him? What's all this about the time it takes a satellite to circle? Once all the pieces come together, it seems like Sturgeon should have stopped, so, for me, the very end feels unnatural and forced. At the time it was published, I'm sure it had quite an impact.