If you don't like costco, you have serious issues.
First of all, what I love about costco is that their products are so across-the-board good that I don't even care how much it costs. But it is a pretty inexpensive place to go, particularly if you buy in bulk. If you were to talk to Dallas G., he would tell you that costco pizza is the best thing in the whole world. I wouldn't go that far but I would say that it's delightful. Other things you can eat from there:
rotisserie chicken--still the best I've found
french feta cheese--creamy and delicious
their kirkland whole grain bread--no hf corn syrup and 5g of fiber per slice
all of the meals in the back that you just throw in the oven
their pecans
their strawberries
their wines
their kirkland vodka
their buttercream cakes OMG
their big ass bags of mexican cheese blends
etc., etc.
But I want to point one thing out: the very best thing at costco is the steak. Whether it's the 6-7 lb beef tenderloin (the least attractive piece of meat you'll ever cook), the 4 pack of filets mignons, or the four pack of ribeyes, I truly mean that this is the best steak you will find in the city. You just have to grill it yourself.
And don't be a philistine. Medium rare, tops.