We shopped for groceries at Costco and Trader Joe's and easily saw which store is better for the average shopper

First, we stopped by a Trader Joe's on Manhattan's Upper West Side.

Outside, we saw some seasonal watermelon on sale for just $3.99 each, which we thought was a steal. The wooden crates were also a nice thematic touch.

Once inside, we took in the atmosphere around us. The walls were painted a light blue hue that blended nicely with the wooden crates that held the products.

The nautical theme of Trader Joe's was apparent the moment we entered the store. Trader Joe's employees are called crew members, and the signs for their designated area was decked out like a ship.

We also periodically heard the tolling of a ship bell, which we found out later was meant to signify a customer in need of assistance.

We started out in the produce section, where we found mounds of fresh fruit and vegetables.

Here too, the seafarer theme was evident. This corn was sitting in a crate that looked like it had just been loaded off a cargo ship.

The prices in the produce section were pretty standard. Single avocados were going for $1.79 each, so we opted for this $4.99 bunch of miniature avocados instead.

These bananas were also super cheap, but it was the eye-popping sign that caught our eyes — and made us chuckle a bit as well.

In general, the signs were made to look hand-drawn, which gave the store a more personal, down-to-earth feel.

The garlic at Trader Joe's was also super cheap because of the company's recent decision to eliminate the plastic packaging around the food. This eco-friendly move is meant to help the company eliminate one million pounds of plastic in its stores in 2019.

Source: Trader Joe's

Impressed with what we saw in the produce section, we moved on to the aisles of packaged food.

Here, we found a lot of products that bore the Trader Joe's name. Instead of the name-brand Honey Nut Cheerios, we found Honey Nut O's.

We had already ranked the Trader Joe's brand superior to the name-brand in a taste-test.

Admittedly, we felt a little robbed of the name-brand products we knew so well. But in many cases, the Trader Joe's brand was cheaper and even tastier than the popular brand.

In some cases, the Trader Joe's product looked almost identical to the name-brand one. These veggie sticks were marked at almost half the price of the more commonly known veggie straws available in other stores like Whole Foods.

Some of the products were harder to compare to name-brands. This cider was brewed for Trader Joe's by one of its brewing partners and we couldn't think of a product that was comparable.

There was no bakery on-site at Trader Joe's, but we did find some chocolate and vanilla cupcakes.

We also found a whole section of different breads, from gluten-free to pita.

Trader Joe's had a great selection of healthy options. We found some shelves filled with different nuts, as well as a hefty supply of dried fruit.

For meals, there were some options in the frozen section ...

... but there were also different cuts of meat to choose from as well. We even found some kosher chicken here.

The lines looked long when we went to check-out, but crew members ushered the process along like clockwork.

When we checked out, we were informed that we could have been entered into a lottery to win a Trader Joe's gift card if we had brought our own reusable bags — yet another eco-friendly policy that made us like the store even more.

We hadn't brought our own bags, so we opted for the classic brown paper bags instead.

We left Trader Joe's feeling uplifted. We loved everything about the store, from the design to the products. But we were still excited to see what Costco had to offer.

We visited a Costco in Manhattan on the east side of 117th Street.

An employee stopped us right away to ask for our Costco card. When he saw we didn't have one, he directed us to the membership counter.

The feel of the store was completely different than that of Trader Joe's. There was no tolling of a ship bell or hand-painted murals on the walls to beautify the space. At Costco, what you saw was what you got.

And what you got was value. The warehouse sold practically everything in bulk.

We wandered through the furniture and clothing departments until we reached the grocery section at the back of the store.

There were no thematically-designed wooden crates here. Instead, everything at Costco looked like it was still in its packaging from another warehouse. We realized we were in for a no-frills shopping experience — and we were ready.

The fruit looked fresh, but much of it was sold in bulk. We did, however, find some watermelon here, each going for about $6.

The frozen section here also had a bunch of meal options, again mostly sold in bulk.

When it came to refrigerated food, we found everything from mozzarella cheese to tubs of coleslaw.

The pre-cut meat selection at Costco was extraordinary. There were a lot of options that all seemed to offer the best possible value.

Kirkland Signature is Costco's in-house brand. And a sign let us know that the food in this section was fresh and of high quality.

The kosher poultry was hard to miss, thanks to another one of Costco's eye-catching signs. In general, the signs here were nothing like the elaborately designed posters in Trader Joe's, but they got the job done.

This store had an entire Kirkland rotisserie filled with different types of meat.

There were even more food options in the front of the store in Costco's in-house food court — though this wasn't technically part of the grocery section.

Costco also had a widely stocked bakery, where shoppers could pick up different cakes and pastries. Another flashy sign proclaimed that the baked goods were kosher as well.

The cakes on display looked delicious. There were a lot of options to choose from and we could even order our own if we wanted to.

There were also some pre-made goodies on sale as well. The options here were pretty standard — muffins, danishes, croissants — but they looked tasty enough.

We saw a kitchen through a window near the back of the store, where we assumed some of the cakes and pastries were being made.

Though we couldn't find any in-house ciders, we did find a whole area of beer that was being sold in large quantities. This 24-pack of Corona Extra was selling for $29.99.

The aisles of pre-packaged products were somewhat overwhelming. However, it was easier to find name-brand products here than it was in Trader Joe's.

We found this four-pound bag of Craisins that looked like it would last us through the end of the year.

But there were a lot of products from the Kirkland Signature label as well, such as these cashews.

Like the Trader Joe's brand, Kirkland has a loyal following of people who swear by the brand. We're pretty big fans of the brand ourselves.

But even with its signature brand, Costco failed to win us over. At checkout, Costco didn't provide any bags for us to put our products in.

Instead, we had the option to reuse packaging boxes to carry our purchases, which could technically be considered an eco-friendly move. However, this process was kind of a free-for-all.

Though Costco had its benefits, Trader Joe's won us over with its charming store design, tasty in-house products, and eco-friendly policies.