There are so many things. One thing a lot of people don't realize is ....
that Trader Joe's prices are lower than many other grocery stores. The other day I was in Trader Joe's and they had posted, on the wall, a comparison of their prices for certain "staples" and another close by grocery store's prices and TJ's prices were approx. $30 cheaper! This included milk, eggs, cereal, fruit, baking mix, hamburger, bread,olive oil, vegetables, and I can't remember what else. I was surprised. Of course I don't think most people just by basics at TJ's.
My cat loves TJ's cat rocks (dry food) and does very well on them. I love their breads, eggs, butter, yogurts, produce, cheese, not a huge offering, but a very excellent array, their nuts and different snacks are great. Their bread sticks and pita chips are two favorites right now. For quick meals their alsactian tart, french onion soup, potstickers, et al., are great, as are their various chicken and turkey sausages.
I really like their evoo, truffle oil, vinegars, sauces, and their spices, while not extensive, are reasonably priced. Their chocolate is very good, especially the dark chocolate and one current addition is their dark chocolate covered mini pretzels. And I'm a fan of their cheap wines.
There is this site for TJ fans, not affilated with the company, that has some interesting info, discussion of products, articles, and even recipes some people have created, using TJ products. They even have contests, LOL.
http://www.traderjoesfan.com/