My favorite word of all the words in the English language is
Motherf**ker...it can be used to express anger, excitement, it can be rude, it can be direct, and in the most literal sense it can be used to describe doing something obscene to the beloved female parent of whomever you are talking to. Or it could even be suggestive and sexy if you tell that same female parental figure that you are a motherf**ker and she takes you up on the suggestion. The only word that has as many unpredictable syntax and usages is co*ksucker. But that one usual is better when said by a woman. A female saying it gives it much more impact. Unless of course the Co*ksucker is also the MotherF**ker. But that would require a more updated dictionary. Next contestant...