Branston Pickle luckily is pretty easy to get in the USA, despite nobody having heard of it. Everywhere I live has had Branston Pickle in the supermarket, although recent it changed from being imported from the UK, to being made in the USA. Luckily, although the USA version is different, its still good (unlike, for example, USA HP sauce).
My wife recently discovered Ribena and is addicted to it, shame because it's effing expensive here!