The most funny, according to Douglas Adams.

Some propose that 42 is 101010 in binary code, others have pointed out that light refracts through a water surface by 42 degrees to create a rainbow, and others have commented that light requires 10−42 seconds to cross the diameter of a proton.

For those who are wonder what the heck is he talking about? The discovery of forty-two (the answer to the Ultimate Question of Life, the Universe and Everything) appears in every version of the Hitchhiker's story. _The Hitchhiker's Guide to the Galaxy_