Well, some are more crass than others. That's pretty much the difference.

As far as meaning goes, the first is grammatically a kind of passive - it's something that happens to you. The others are active ie actions. In terms of acceptability, the ascending order of vulgarity is 1, 3, 2. F**k is offensive in most cases, whether you're talking about sex or not. 99% of the time when this word is used it has nothing to do with sex - it just shows anger, frustration, surprise - any emotion you can think of. It also shows a lack of imagination when it comes to vocabulary. 'Screw' has a lot of other uses which are informal but not necessarily vulgar. 'We're screwed' means 'we're in trouble' and 'I've screwed up' means I've made a big mistake. I'm a fairly genteel sort of person, but I'd happily use either of these phrases. 'Get laid' is perfectly inoffensive if you're talking about tables, napkins and cutlery.