The "F Word" is an extremely obscene word in the English language.
I don't know that it's any more obscene than others. For mine, there are worse words, yet one could use them in front of a police officer and not be arrested. I suppose it depends on one's personal perspective, though. For many, the f-word is just a part of every day language to help describe various situations, while others see it as a sexual term and therefore vulgar.
I wouldn't use it even if someone paid me to do so
Hehe, I would! And the more they paid me the more I'd use it. I so enjoy parting fools from their money. 
For me, though, it's a matter of context. For example, when used in the sexual way, I think it is cheap, nasty and demeaning. If it's used as an exclamation of pain when one hits their thumb with a hammer, or to express shock or surprise, then it isn't sexual and thus 'more' acceptable. Having said that, I don't like it when used repeatedly during conversations or just for the sake of it. To me, when someone cannot express themselves without using the F-bomb every second or third word, then that is ignorance.
