Oh yeah… almost forgot. Butter. We get butter based on cost and date.
Really? How old can a battery get from a discount store? And how “fresh” can a battery be just because of it’s brand? After all, the maker of a product normally doesn’t have much control over its retail distribution. When the “freshness date” of a battery is ten years into the future, I find it hard to imagine delays in distribution from discounts stores making much difference.
Marcal toilet paper. Oh, I’d buy something else if I couldn’t get it, but as long as I can get it locally, that’s all I’ll use.
Tampax tampons and Always pads. Yes, we women hate those “Have a happy period!” ads, but my periods, which I unfortunately still have, are much less unhappy thanks to Always products. 
Maruchan ramen noodles. Yeah, they’re cheap, but I like them for a quick snack sometimes.
I will try most generics. A lot of generic canned foods just can’t match the taste. Sugar is one thing that puzzles me, how can one brand really be better than another.
nm
Name brand:
Soda Pop- coke, pepsi, a and w, sunkist,
Toilet paper- Quilted Northern
Coffee-Cains
Toothbrushes-Butler
Band Aids
Computers-HP
Lightbulbs-GE
Chocolate-Hersheys, Cadbury.
Also, stuff that can be id’d as being either name brand or generic, such as sport shoes (Reebok, New Balance), that I wear to work. (Don’t want people to think/know that I’m a cheapskate.)
Generic:
Everything else. Usu. Great Value, from WalMart, but, some stuff from Aldi’s house brands, or Dollar Tree.
Somewhere like Wal-Mart, Target, etc… it won’t make much difference- the Rayovac house brand batteries are always up to date. Generally speaking, they’re at least 3 years in the future, usually a lot more than that.
However, at other stores and online, you may see off-brand batteries like say… ACDelco, Kodak, etc… without printed expiration dates, or dates that are a couple of years away, not nearly 10 years. They may have received 5 containers of batteries from China in 2006, and are just selling them until they run out.
While the batteries are almost certainly not dead when the shelf life is up, their capacity is probably much reduced from what it was when they were originally manufactured.
The big boys aren’t going to fool around with their brand by selling old batteries, but somewhere like Harbor Freight isn’t going to have such concerns.
So if you buy new 2014 manufacture Duracells and compare them to some crappy generic batteries you got at Harbor Freight made in 2005, it isn’t surprising if there are capacity differences. However, 2014 Harbor Freight batteries are probably right up there around 2500 mAh with the Duracells.