5 Things That Are Always Worth Buying at Costco

I've had a Costco membership since the U.S. invaded Grenada (1983, for all you history buffs). Through the years, I've seen plenty of my favorites come and go. However, there are some items I can count on to be available anytime I shop. Not only do these five products stick around, but they are legitimately worth every penny I pay.

1. Bed sheets

If you happen to notice that people you run into seem a little crabby, it may be because they're not giving their bodies enough time to rest. According to Gallup, Americans sleep, on average, 6.8 hours a night. That's one hour less than we slept in 1942, and less than the seven to nine hours recommended by experts. You know how toddlers fuss and stomp their feet when they're tired? We adults do the same thing.

All that to say, sleep is vital, and because I know how miserable I am when I cheat myself out of rest, I'm all about having a comfortable bed. For me, a comfortable bed begins with a great set of sheets.

Costco is where it's at when looking for soft, comfortable sheets that won't empty your checking account. For example, Costco's Hotel Signature 800 Thread Count 6-Piece Queen set is $100. What's great about 800 thread count sheets is that they're soft and dense, two great features if you're looking for luxury.

In comparison, Amazon's Hotel Signature 800 Thread Count set is $135.

You might not always find the set you want at Costco, but it pays to check. Besides, if you're in the store, you can feel around until you find the ones that make you want to crawl into bed for some shut-eye.

2. Rotisserie chicken

There are plenty of reasons shoppers snap up Costco's delicious rotisserie chicken. For one, they're perfectly seasoned, and at roughly three pounds, they can feed a family. Oh, and they're also only $4.99. What's not to love about serving a picture-perfect chicken rather than slaving over a hot stove? Heck, a few aisles away, you can pick up all the sides you need to round out the meal.

To give you an idea of what a bargain these are, we check a couple of other stores famous for their ready-to-serve rotisserie chicken. Jewel-Osco's version (which is also delicious) is $6.99, and Walmart's is $6.97.

3. Kirkland Signature Flex Tech 13 Gallon Kitchen Trash Bag

You know what I can't stand? Paying for trash bags. The idea of handing over money for a product that's going to, literally, end up in the trash is more than my savings-obsessed heart can handle. Even worse is when a trash bag leaks all the way from the kitchen to the garage.

With that out of my system, these Flex Tech bags truly are the best. You can get 200 bags for $21.50. That's less than $0.11 per non-leaky bag. And when they say "flex," they mean flex. These things can hold far more than you might expect, which is what I want.

In contrast, Walmart's Great Value trash bags cost a little over $0.15 a piece. Home Depot's Flex Pro 13 gallon bags are over $0.13 each, and the Amazon Basic Flextra trash bags run $0.20 a piece.

4. Kirkland Signature Baby Wipes

My boys graduated from college and started families of their own years ago, and yet I continue to purchase baby wipes. For me, they're the Swiss Army knife of quick cleanups. For example, last weekend, my husband and I visited family in a nearby state. As we were driving home, he spilled coffee all over his pants.

No problem. Cleaning up was as easy as reaching behind the passenger seat for a package of baby wipes. They're just wet and thick enough to clean a mess. Wet wipes are also great for cleaning sticky fingers, wiping down dogs who smell a little too "earthy" after rolling in the grass, and even cleaning mud off floor mats.

And here's the deal: You get 900 baby wipes for $22 at Costco. That's less than $0.025 each.

5. Shelled pistachios

People have been eating pistachios for thousands of years. In fact, archaeologists believe mankind began eating them as early as 7,000 B.C. However, it wasn't until the mid-19th century that they came to the U.S.

As long as your stomach can handle the pistachio seed, there are tons of health benefits, including:

• High levels of potassium and unsaturated fatty acids, both with antioxidant and anti-inflammatory properties.
• May lower your chances for cardiovascular disease.
• Full of fiber and minerals.
• Can make you feel fuller longer.
• Adds good bacteria to your gut.

Plus, you don't even have to shell them yourself because it's already been done for you. If you're a snacker like me, pistachios can be a healthier option.

Kirkland Shelled Pistachios cost a little under $0.71 per ounce. At Walmart you'll pay $0.98 an ounce, and at Target you'll shell out $0.96 an ounce.

Naturally, saving money is important, but it's not the only consideration. Your favorite Costco items are likely to be the things you use regularly and can't imagine buying anywhere else because they work so well for you.