Wal-mart has its place for me. I have a Costco card, so 70% of what i need can be found there, and typically it's of better quality than Wal-Mart. I usually only shop there when I just CAN'T find it anywhere else for a price that isn't cheap, or at CostCo. CostCo for me has its place, the problem is that it really is a sort of lottery when you go there for non-food items. Of course, they're going to have things like tires and car batteries, however they might not have that HID light cannon that I want.
I also pretty much am set in terms of stuff that I need/want. The stuff that I do buy typically is fixed-price or has the best deals on the internet (specifically: computer gear and Apple stuff).