One of my favourite things about going to Canada is the Caesar cocktail. On first blush it's just a Bloody Mary with clam juice in it. But it's much better. In Canada they make them well, they make them spicy, and they make them often. Ask for a Bloody Mary in the US and you're likely to get a strange look and a glass of tomato juice with some vodka in it. Ask for a Caesar in Canada and you get a lovely well made drink. The clam juice is pretty good, too.
4 parts clamatoSo now you know why Clamato exists. More on MetaFilter.
1 part vodka
salt and pepper
tabasco or horseradish
celery salt on rim