I like their meat, seafood and bakery items. I don't even bother going down the rest of the aisles, I only buy things that are on sale out on the ends. If it's not on sale, I can get the same thing cheaper at Superstore, and I don't get a headache when I shop there.
We did get an absolute kick ass deal on new iPhones last week though. I even switched carriers because it was too good to pass up. I had no idea Costco did wireless, but they do..and they do it well. We walked out paying less than $100 for two 6S's with warranties, covers, car chargers included, and $1000 in credit on the first 6 months of our bill. The food we bought cost nothing because we used the cash cards that came with the phone deal, and I left with an $8 credit still on one of the cards. So that was well worth the trip!