"Penultimate" does not mean "the best" nor does it mean "most ultimate." It means the one before the last. Second to last. Not the last; not the best; not the squeal-with-happiness ending.
So if someone tells you "that was the penultimate sucker punch," you might want to brace yourself, because another one is coming.
(This aside is brought to you by the letter "Y," the number 6, and a teacher for whom the discussion on the word led to GREAT BIG GIANT SHOUTING LETTERS and I'M A TEACHER AND YOU'RE NOT SO LALALALA SHUDDUP*. Don't blame me; I just witnessed it. And I weep a little for her students.)