1. Frozen fruit
    Frozen fruit makes a great healthy dessert, but it's even better blended into smoothies, which are ideal snacks or meals for people who don't like to cook. Since the fruit is frozen, it chills your smoothie without watering it down like ice does. My picks: mango, strawberries, blueberries, raspberries, and pineapple.
  2. Nuts
    Raw or roasted, salted, flavored, or plain. Nuts contain protein and good fats, provide an excellent source of energy quickly and will keep you satisfied for awhile. They also add great crunch to salads.
  3. Since this is basically my shopping list: smoked salmon. Good for breakfast, on crackers, in salads, in pasta, etc etc.
    Suggested by @allison
  4. Dense, whole-grain bread
    You want something with good amounts of protein and fiber. Most likely it's not going to be very good raw, so toast it before using.
  5. Avocados
    Avocados are a delicious source of healthy fat, and fiber. Put them on the aforementioned toast with some salt and pepper, layer them into a sandwich, or eat them straight, with a spoon, topped with a little salt.
  6. Eggs
    Hardboiled, scrambled, fried, poached, etc, eggs are an excellent, cheap source of high-quality protein. If you tend to be in a rush in the mornings, hardboil several eggs in advance, then peel and eat on your way out the door.
  7. Salad greens
    If you're not big into cooking, buy greens that are pre-washed and ready to go. My favorite mix from Trader Joe's is called the Cruciferous Crunch Collection. I also love plain arugula and baby spinach for salads. Don't be afraid to make your salads really hearty. Top them with nuts, cheeses, avocado, dried cranberries or raisins, and anything else that you love. Your salad should be filling into to be a full meal.
  8. Cooked chicken
    Hit up your grocery store's salad bar (Whole Foods has a great one) and fill a container with grilled or roasted chicken. Alternately, buy a whole rotisserie chicken and cut it up at home. This can be tossed into quesadillas, salads, simple pastas, or even just eaten plain for a quick, healthy protein boost.
  9. Canned tuna, packed in olive oil.
    You will never eat water packed tuna again after you taste Italian olive oil-packed tuna. The olive oil keeps it extremely moist, and it doesn't get that overly fishy flavor that the water packed kind can get. Flake it over greens or toss it with sliced red peppers and tomatoes, salt, pepper, and lemon juice for a classic Italian tuna salad.
  10. Crunchy vegetables to eat raw
    Keep carrots, celery, radishes, mini bell peppers, and any other raw veggies that you like at eye level in the refrigerator. Make them your go-to snacks.
  11. Fresh fruit
    It seems obvious, but it's easy to forget. Buy fruit that is easy to eat, and doesn't require prep beyond washing it. That way you're more likely to eat it consistently.
  12. Oatmeal
    Oatmeal is so easy to make, and it is such a healthy breakfast (or lunch...or dinner). You can make it sweet, with a little bit of brown sugar and cinnamon, or you can make a savory porridge, kind of like risotto, with a little bit of grated Parmesan, salt, pepper, and olive oil.
  13. Lighter cheeses
    Snackable cheeses like mozzarella (bocconcini--little balls of fresh mozzarella or string cheese), sliced havarti, or Babybel cheeses make great low-carb snacks, or toppings for salads.
  14. Yogurt
    My pick is usually plain low-fat, but not nonfat (a little bit of fat helps keep you full longer) Greek yogurt. Plain yogurt is much more versatile than the kind with flavorings in it. Top it with any fruit you like, honey, or my favorite: a tiny bit of olive oil, salt, and pepper.