What is the funniest story ever?
The LAPD, The FBI, and the CIA are all trying to prove that they are the best at catching criminals. The President decides to give them a test. He releases a rabbit into a forest and each of them has to catch it.
The CIA goes in.
They place animal informants throughout the forest. They question all plant and mineral witnesses. After three months of extensive investigations they conclude that rabbits do not exist.
The FBI goes in.
After two weeks with no leads they burn the forest, killing everything in it, including the rabbit, and they make no apologies. The rabbit had it coming.
The LAPD goes in.
They come out two hours later with a badly beaten bear. The bear is yelling: "Okay! Okay! I'm a rabbit! I'm a rabbit!"
No, the word 'funniest' is not a noun at all. The word 'funniest' is the superlative form of the adjective funny (funnier, funniest). Example: That is the funniest story the I've heard for why you don't have your homework. The the word funny (funnier, funniest) is the adjective form of the noun fun, a common noun; a general word for any fun of any kind.