The #1 thing for me at Costco is the gas. I have the credit card, so I get 5% cash back on the first $7,000 of gas I purchase in a year. Being as that, as of now I am spending ~$70/week on fuel, I will not hit the max for the year.

But 5% cash back on ($70*52=)$3640 means I get $182/yr by default back to cover the $130 annual cost of the executive membership. Doesn't sound like a good deal until you also factor in that their fuel is typically 10 cents a gallon or more cheaper than the next least expensive fuel place, which means that for my roughly 650 gallons of fuel a year baseline costco gas saves me an additional $65.

So yeah, nothing really amazing, but the fact that having the membership lets me pocket something in the neighborhood of $120/yr on top of the occasional shopping trip and access is nice.