Here's one of my favorites I've just this moment remembered.
"The New One" by Fredrick Brown, loved the ending in this one!
Also try "Scanners Live In Vain" by Cordwainer Smith, "Surface Tension" by James Blish, "Two Dooms" also "The Marching Morons" and in the same universe "The Little Black Bag" (short story) all by C.M.Kornbluth, plus the Fafhrd and Gray Mouser stories by Fritz Lieber a lot of which are novellas, loved "The Bizarre Of The Bizarre" (short story), just imagine the surprise you would have if you bought the contents of the giant bird cage!
And of course not to forget "The Big Front Yard" by Clifford D. Simak, "Second Variety" by Phillip K. Dick and "Exploration Team" by Murray Leinster also don't miss his short story "A Logic Named Joe" published in 1946 which predicts the internet!
Plus one of the greatest novellas of all time (pun), "The Time Machine" by Herbert George Wells!!!
If I can think of any more I will let you know.
P.S. Hitmouse , I have the same book, it's where I read "Waldo" but it's been a long time since I've read it.