For absolute low prices Walmart seems the lowest. Target however has some stylish and interesting products that are inexpensive but nicer or better designed than what you find at Walmart. Best Buy sells electronics though now I see appliances and music in larger stores. Their prices seem average though their employees are generally helpful and knowledgeable. I've definitely benefited by Best Buys' service plan because it has replaced several things I bought there that broke after the warranty period had passed.
Walmart's prices are significantly lower on most items, but as always there's a trade off. I suppose you'd have to be more specific about what you wanted the deal on.
I'd say Wal Mart.. not sure what ''Best'' is unless you're talking about Best Buy. I love Target, but their prices are definitely higher than Wal Mart's.
Wal Mart Save Money live better
mostly everything :P