I second the cold chicken -- to be slightly healthier, it's as easy as stopping at the store the day before to get a rotisserie and refrigerating it overnight. I also love couscous salad -- cook couscous, chill, then mix with some feta, chopped olives, greek dressing (or just lemon juice and olive oil), green onions, diced tomatoes, fresh mint or basil, whatever really floats your boat.
I also like a curried chicken salad over lettuce: mix together FF yogurt with lemon juice, curry powder, salt/pepper to taste, add in some halved red grapes or raisins, cashews if you like, then add in chopped rotisserie chicken, serve over chopped lettuce. Even DH likes this and he is really not a chicken salad guy (achem, or really a salad-in-general guy, to be honest

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Another good thing is to season some (shell-free) shrimp with cumin, salt and pepper, grill, then chill. Dice some avocado and some roma tomato, mix together with lime juice, salt, pepper, (add cilantro, even jalapeno or garlic if you like). Take along some flour tortillas, serve the shrimp in the tacos with the avocado topping.