I do the half mayo, half low fat sour cream, and mine has to have eggs. I love eggs in my potatoe salad. Now that I am a Fage fan, I couls swap th ehsour cream for the lf sour cream. I use a similar blend for chicken salad. For seasoning/add-ins in my potato salad, I use celery, red onion, some vinegar or I could use sweet pickle juice, but not too sweet or sharp with those, salt, fresh groung black pepper, fresh choped parsely. That is about it. Oh, when the potatoes are hot, I toss with a splash of olive oil and cider vinegar and salt and pepper. I think I got the general recipe from Silver Palate or ther New basics cookbook, and I do it from my head now. I rarely measure for any meals that I cook. Only the first time with a recipe, then, I generally do it from my head.
I had a friend once do a potato salad that also had some jicama and diced ham in it. it was very good. I have done a Moosewood one, that had extra veggies. it was ok, but not traditional. My crowd liked it, but they like odd salads, something different.
Cole slaw. Hate heavy, drippy cole salw. All I do is a bit of light mayo, apple cider vinegar, small amount of sugar or honey, celery seed, scallions, and salt and pepper and toss it all with a bag of the shredded slaw. If I shred my own, I will do more red cabbage than is in the bagged mixes. Love the color. Like it heavy on carrots too, if I do my own work. I would not think to add raisins to it and the thought turns me off. I like the fresh, clean taste, and making it too sweet would ruin that.
I do like german potato salad too. I will try most, but tend to find store made ones too pickly and wet.