A few reasons. It was the first Shakespeare quote that I was introduced to - all be it in a way of parody through Star Trek. Hamlet is also my favourite Shakespeare play, and finally. But I think it ultimately comes down to the question, which is so profound, and truly shows how wretched the character is feeling. It is a question that many unfortunately face and ask themselves.
Mostly I don't understand Shakespeare but I like the 3 witches and their "Double double toil and trouble, Fire burn and Cauldron bubble" and I quite like “With mirth and laughter let old wrinkles come.”
― William Shakespeare