Wow, I'm surprised at most of the replies. I only have experience with Lowes, Home Depot, and Walmart. I HATE all three of them. They are horrible stores and the services is bad at best. I especially hate Walmart. They are crooks.
I cannot remember a time when I went to Lowes for a project and only needed to make one trip. So many times I have bought something from them and gotten home only to find that what was in the box was not correct or was missing parts.
Walmart incorrectly marks the prices on their products. When this is pointed out to the manager, they say thanks for letting them know and then don't change the price. If you threaten to contact the AG, they will hand you a $10 gift card and still not change the price. When I contacted the AG, they just get a form letter from Walmart that says it's all taken care of. The form letter gives you no way to actually contact Walmart. When a kid product got squished onto my berber rug it hardened. Walmart said they had no idea what the product was, what it was made of, or who even sold it to them. It completely ruined the carpet, but they told me they didn't care. They still were selling the product on the shelf though. OK enough ranting...