I like to use a sesame ginger dressing and some organic apple cider vinegar instead of mayo or anything. I add usually add edemame (even more protein!), onion, and whatever else I have. I'll add celery, shredded carrot or broccoli stalks.
Another one I like is black olives, onion, artichokes (in water, not marinated in oil), fresh tomato, pepperoncini, maybe a little feta if I have it, just with some spices and mixed.
I'll also go classic but sub brown spicy mustard for mayo, and dill relish for sweet,