Well, as much as I like my .357 revolvers. If I could have one gun I would have to choose a Glock. I have a .40 S&W Glock 27. If I were buying my only one I would have the model 22 because of the capacity and longer sight radius. The standard frame fits my hand better than the larger 10mm or .45 ACP frame. They are accurate, rugged, have a simple mechanism, perform well in bad conditions or when dirty, & I can repair them quickly with few tools. If the .40 S&W dries up I can cheat & change the upper and magazines and have 9mm, .357 SIG (just the barrel), or 45 GAP.
I like the .40 S&W because it has similar performance to .45 ACP & .45 GAP and more punch than 9mm. It also has more capacity than either of the .45s. 45 GAP is harder to find than the others. Even in the current ammunition drought, I have been able to find .40 S&W as often as .357, .38spl, 9mm, & .45 ACP.