For me personally, it comes down to two things. The ability to find what I'm looking for, and the help from a store employee who can help me find what I'm looking for if I can't find it by myself.
Which is why the local family-owned business is my first option on most day-to-day things. Even if I have to pay a few bucks more, but it's worth noting that it's 2 miles from my house and much more convenient.
For whatever reason I find the local Home Depot store cluttered, unorganized, and quite frankly - nasty. I'm not fond of walking into any business where there's cigarette butts, empty soda cans and candy wrappers littering the front entrance. The few times I've been there - I've had to wait 20+ minutes to talk to an employee about where to find something, and then the employee has no idea what the item is I'm looking for, much less where it is (if they even have it) in stock.
The Lowes store during lunch hour can be trying, but I've learned to avoid going there when part of their staff is taking lunch. Otherwise I've always had good experiences there, and know where to find stuff. And they most always have whatever it is I'm looking for, which means I've not wasted an hour of my life driving there and back.