I'm picky. When I make a salad, I usually put canned or grilled chicken on it, mushrooms, seeds, and cucumbers with vinegar or salt.
Some people like to use fruits such as mandarin oranges and sliced strawberry with nuts. I've found that fruit based vinagrettes taste good with these types of salads.
Another healthy option would be grilled corn, cooked peppers, onions, and black beans. Perhaps add tortilla strips and/or chicken for a filling salad with a mexican feel.