There are many, many Happy Donuts shops in San Francisco. But for our five bucks, the store at 3rd and King streets delivers the most savory egg salad sandwich of 'em all — or of any other eatery in the city, for that matter. Most places err by overloading their egg salad with veggies, assaulting taste buds with a fusillade of onions, celery, and green peppers. Too many other eateries use eggs and mayo that taste like they've been extruded through a sewage pipe. Happy Donuts gets the deceptively tricky sandwich just right, calibrating the ratio of eggs and mayo to veggies with atomic precision. The result is a sandwich — including the bread of your choice, of course — that leaves your mouth feeling like it's had a deep-tissue massage. And without so much as uttering the word "combo," you receive a bag of chips and a side of potato or macaroni salad to complement your meal. Happy, indeed.