want2b - there's a difference between security & immigration.
i live in the US so prob have a similar range of experience to you - i would say that no particular country stands out as better/worse.
i found munich to be vvv thorough, but slow, belfast rude but efficient, detroit lovely, denver slow and heathrow the quickest.
a friend of mine used to travel on a South African passport & routinely had full body searches (naked ones) in every country she went to/from. also, going to the US embassy in london, babies, pushchairs etc all get searched.
actually, it doesn't matter whether you're travelling with your dh or the queen - for immigration you should go through the correct line. being 'confused' and getting in the wrong line is a standard ruse used by people who don't have the right travel documents.
either we should accept that security = invasion of privacy, or just accept a higher terrorist risk.
the only really safe way is for everyone to go through naked, pick up a credit card once through security, then buy what they want to take with them once through. but none of us would agree to that, so fingers up bums it is.
(though, in response to op, it should be done with some empathy)