This video tests the myth that a Model M keyboard can be used to kill a man and you can still type on it afterwards.
“Model M vs Zenith Bull—Keyboard Carnage [1]”
While the proper designation is the Model M keyboard, I know them as the “IBM PS/2 keyboard” and it's the only keyboard I use on my computers.
And yes, they are very tough.
About the only keyboard tougher than the IBM PS/2 keyboard is the original IBM PC 84-key keyboard—forget the high impact plastic, this keyboard was made of metal!
But alas, you can't use those on modern machines, so the next best thing are the PS/2 keyboards.