An annual pilgrimage as a born and raised Calgarian. Even when I lived in Toronto for almost 5 years I still seemed to end up back in Calgary most summers in time for this 10-day city-wide takeover.
While things on the grounds don't change very much year to year, there's always a draw. It might be the new deep fried foods, the rodeo, all that crap you don't need inside the Roundup (BMO) Centre, or the chance at being that guy lugging around the giant prize from the midway.
Outside the grounds there's always a ton going on elsewhere downtown and around the city. If you're paying for breakfast during Stampede, you're doing it wrong.