Oh, I'm totally on board with you on this one! Living in Canada I cannot get all the candy (or sweets as we called them) from back in UK. I'm heading there in a couple of months and will be hunting down some of my old favourites like: Toffo's, Fruit Pastilles, Outer Spacers, Football Crazy Crisps, Jaffa Cakes, Lion Bars, Texan Bars, Spangles.....the list goes on and on....
Petenali: Wooohooo! Same here, but I miss South African sweets and chocolates (very similar to English: Cadbury and Nestle!) The local supermarket is now bringing in some English goods (Cadbury Fruit 'n Nut my fave) and guess what? Got Pastilles!
For me, it's a Hershey's Whatchamacallit bar. Whenever I am away from an area where it is readily available I miss it terribly.
Sadly, as of 2008, the flavor of Whatchamacallit, along with some other staple brands from Hershey's, has changed somewhat. Many people claim not to taste the difference, but when they stopped using cocoa butter in their formula the change was detectable to me. It is still a special treat for me, but I would literally jump with joy if the original ingredient mix would be brought back.
It was called Milkshake and it was made when I was a kid. Naturally, it was discontinued by Hollywood, who made it. I did find it in a drugstore in Wilmington, DE in my 40's, but that must have been the end of it. The company refuses to make it again.