What can you say about Wal-Mart... It's Wal-Mart!
I think the thing I like is the super-store so I can get everything in one spot. No need to shop around, overall they have the lowest prices and if you found lower, it wouldn't be worth the cost of gas to save a few cents.
I will buy pantry items but don't trust the meat and the produce is OK but kind of lower grade products.