I love potato salad but very rarely like one that isn't homemade. There are three in my repetoire that get chosen at random, my mom's potato salad (which I think came from Gourmet magazine long ago) which is full of onions and nicely tart, Nanny's potato salad (not my Nanny, but that of my friend Angie) which is full of olives, and this one which came from Cook's Illustrated.
My mother says that this potato salad reminds her of the one that her mother used to make. Occasionally her mother would substitute chopped dill pickles instead of using sweet as is mentioned below. It is a nice variation and one that I make sometimes just depending on my mood. Also I will sometimes use red onion instead of the scallions.
American Potato Salad
2 pounds Red Bliss or new potatoes, boiled, peeled, in 3/4" cubes
2 tablespoons red wine vinegar
1/2 teaspoon salt
1/2 teaspoon ground black pepper
3 hard boiled eggs, in small dice
2-3 scallions, thinly sliced (app. 1/2 cup)
1 small celery stalk, in small dice (1/2 cup)
1/4 cup sweet pickle (not relish) cut into small dice
1/2 cup mayonnaise
2 tablespoons Dijon-style mustard
1/4 cup minced fresh parsley
Layer warm potato cubes in medium bowl; sprinkle with vinegar, salt and pepper as you go. Refrigerate while preparing remaining ingredients.
Mix in remaining ingredients; refrigerate until ready to serve.