I never pass down an opportunity for a trip to Costco. I love it there. It's quite a liberating experience in itself. Hungry? Awesome food court, fun sampling. Bored? Check out their books/gadgets/random crap. Big party? Don't bother going to walmart, buy in bulk at Costco and save of course.
They always have fresh fish, the salmon is thick and tender.
The optical department should be checked out as well. I usually bring in my prescription for some snazzy new frames that cost half of what eye doctor chains cost.
You'll always leave with treasure/a great deal. I love Costco. It is a must-go. I even drag friends down here when they tell me they've never been.