Wash the potatoes and place them in a medium saucepan. Cover the potatoes with cold water and add a generous amount of salt to season.
Bring the water to a boil over medium heat and cook the potatoes until they are fork-tender, about 8-15 minutes depending on their size.
Drain the potatoes and let them cool completely. Once cooled, peel and cut them into bite-size pieces.
In a large mixing bowl, combine the mayonnaise, sour cream, mustard, vinegar, chopped pickle, sugar, salt, and pepper. Stir until well blended.
Add the potatoes, chopped celery, green onions (or red onion), red bell pepper, and hard-boiled eggs (chopped). Gently fold everything together until evenly coated in the dressing.
Cover the bowl and refrigerate for at least a few hours or, ideally, overnight. The flavors will develop and taste even better the next day.
Before serving, give the salad a light toss and adjust seasoning if needed. Enjoy!