frak off - motherfrker - let's frack - fraked up
Characters use it from the start and we pick up on it quickly. We take it to be an example of semantic shift and although it seems odd at first, it works.
Thing is though, as much as it works, it just doesn't compare with the impact of the real 'fuck.' It's a step closer than shows like 24 or The Shield that have no strong swearing. Shows don't depend on swearing, but a great deal of credibility and believability is lost when all a guy who's just been double-crossed and left for dead can say is 'damn.'
Take The Wire. The characters swear in The Wire, a lot. One particular scene, one of the great scenes of TV history, has our two heroes Bunk and McNulty investigating an old crime scene. This scene is the best part of ten minutes long and literally all Bulk and McNulty say throughout is 'fuck' or variations thereof. It shouldn't really work, but it does. It's a powerful, indulgent scene that says so much more than a lot of crime procedural waffle.
I'd like to analyse this scene but I'm sure there are already many essays out there on it written by people with greater insight and verbal dexterity than me. So I just want to remind everyone who's watched The Wire of that scene. I just want you to remember watching it for the first time. I want you to smile as you reminisce. I want a shiver to run through you as I'm sure it ran through you nearly every time you watched an episode of The Wire. For anyone who hasn't watched it - you must, if just for that scene.