Sam, as a British Citizen who has spent far too much time traveling through the UK border, and as a world traveller who's been through his fair share of borders, I'd agree that other countries are tricky, maybe even trickier.

However, I'd have to say that the most nerve-wracking insane experience is the US border. You cannot believe policies, as they are implemented in strange and weird ways, dependent on the officer you get to speak to.

Who are all armed. And trained in special-ops interrogation techniques.

I'd say Israel is on par with that, (though i haven't been through), however they fear daily attacks in Tel Aviv, so there's plenty to worry about.

The US Border - possibly the most trafficked today, is also the most hostile compared to what it _needs_ to be. It doesn't even matter if you are a visa waived traveller, you still go through the same crap as if you were on any other visa.