This is beginning to sound like a British ex-pats thread.
Gotta chip in my 2-cents worth as another ex-pat Brit in the US.
Yes, British chocolate is the best. Like someone said earlier, American chocolate is just wrong. My wife couldn't believe the difference between US and UK equivalents of chocolate bars (KitKat, Twix, Snickers (Marathon

Strangely, the Creme Eggs around here this year were actually made in the UK. Proper ones

Luckily for me, there are a couple of 'British' stores around me so I have access to most things I miss, albeit at a cost.
And as 'Yoda Is Your Father' said, cheese is the other thing I think Americans have no clue about. Sharp cheddar ! Um, what exactly is meant by sharp. A little more 'no-flavor' than mild cheddar. I'll take a mature UK cheddar any day of the week. Again, I can get hold of a pretty large selection of cheeses from the UK and Europe where I am, so I'll consider myself fortunate on that front. Now where's my jar of Branston...