Most of them? Generics are frequently the same thing from the same manufacturer with cheaper packaging and no/very little marketing. There are very few things I've ever tried that were noticeably better in the name brand.
The store by me has their own brand of pop-tart that's got more icing and filling as well as being half the cost. They don't have as many flavors, but they're not shrinkflated to the point of being a sad cookie. Shout out to Meijer toaster pastries.
I'd say the other way around. The store brand version has nearly always been fine, in my experience. I'd instead use the store brand and make a list of cases where the store brand isn't okay. At least in my experience, it's pretty limited. What I can recall having bad experiences with, off-the-cuff:
Soup. I have had some pretty disappointing store brand canned soups.
Things with motors, like small kitchen appliances, blenders and the like. I've had a bunch of generic ones of those fail before.
Sodas. These aren't exactly the same. Some people particularly prefer the taste of one root beer or whatever, and it might be that they prefer a name brand. That being said, there are also people who prefer store brands, so...shrugs
There are also a few cases where I've run into a particular brand that doesn't have a store clone, and where I really like the name-brand product.
Pretzels. I particularly like Dot's. I haven't seen a store brand clone of Dot's.
Sardines. Bit of a niche, but I once went on some website with some guy that was absolutely rabid about sardines, reviewed them, wrote huge amounts about them. My dad always liked eating canned sardines on crackers. Tried a couple different brands, and yeah, there is a difference, but the big one is that stores in the US don't normally have heavily-smoked sardines (well, okay, sprats) in oil. I started eating Latvian "Riga Gold" sprats in oil, and they're just amazing. I don't like a lot of foods I've tried from Eastern Europe, but man, they hit it out of the ballpark on that. I don't think that we have a US-based comparable manufacturer.
Red Windsor cheese. It's not all that fancy, just cheddar with some port wine marbled in, but I really like the taste. Same thing on this -- I don't think that there are any companies in the US that make the stuff, so it's name brand or nothing.
If someone did clone any of the last three, though, I'd give 'em a try.
Recently I've been buying the grocery store brand cereals. They're half the price and I honestly find them tastier and made with better ingredients. Kellogg's quality has gone down the drain and it's really noticeable when you switch over.
Personally I don't care about brand names but about quality, as long as it's not shit just buy the cheaper options. Mostly the brand stuff isn't worth it, at least here in Czech republic but here's whole different problem with us getting all the shittiest products from EU.
In Canada, No Name Brand. All the products are in non eye-catching packaging, and are quite cheap. They are quite popular with the college and university housing crowds.
Honestly, i've always approached this question the reverse of how it's posed here. Pretty much every store brand whatever is just fine.
But, picking a few fancier versions of things as exceptions is nice sometimes.
Lately for me, Kingdom aged organic cheddar and Kerrygold butter have been my indulgences. I don't eat much dairy, so they last me a long time. They're loaded with flavor. And, it's just nice to have a few things that feel special.
I guess you need to define "fine". Most things are fine to buy but some name brand items are, in my opinion, worth spending more on.
For example, for me it's certain condiments and spices. Red pepper flakes by a name brand such as McCormick just taste better and have a more potent flavor. Buying a generic brand is just "fine" - it gives a good kick to food - but it doesn't nearly taste the same or is as flavorful as the name brand. In my opinion!
Store brand frozen vegetables and canned vegetables are fine, however I've found that there's a huge difference in quality where canned beans are concerned. Generic refried beans are just awful, as are generic baked beans.
Hard to say. Gotta check the labels because I've noticed a lot of the store brand items (especially at Walmart) have known carcinogens in the ingredients.
Noodles. Premade sauce in jars, that's a different story, but the noodles themselves ... I simply can't taste any difference, so why should I pay five times as much for the same amount of noodles?
Same with rice. I usually buy a huge bag of no-name rice from a nearby overseas market every couple of months, which is a lot cheaper than buying the same amount of rice in small bags, and doubly so if said rice is a brand name grain.
There's a lot of them. I find it easier to classify by the store. For example, Costco's and HEB's (in Texas) store brand products are considered great (and sometimes even better) than their branded counterparts.
Depends which store brand too. Costco stuff (Kirkland) is almost always really good. Safeway has a good store brand too (O Organics and Signature). Kroger's are like, okay (Private Selection). Walmart's (Great Value) are hit or miss. Natural Grocer's stuff is usually good, and Trader Joe's is usually great. Target's Good and Gather seems good though I haven't tried many since I rarely go there for groceries. Uh... so I guess I mean pretty much everything.
Dollar Tree has "thin mints" that are just as good as the real thing. Kroger does as well but they cost like twice as much as they would from dollar tree.
Publix Monterey Jack cheese is, oddly, better than the other brands. Like it's the first one I ever tasted that wasn't just rubbery nonsense. Their milk and butter we like, and their coffee is good.
Whole Foods store brands are all pretty good stuff.
I buy any brand of canned beans (I don't buy refried beans, I refry them) or dry beans, unbleached white flour, egg noodles, fizzy water (though I do prefer Topo Chico, it's a weak preference), sugar, and a lot of what we buy is fresh fruit & vegetables, they mostly aren't branded.
I would say pretty much anything. The only time I got a cheaper brand and absolutely hated it was when I saw a pack of Bar-S hot dogs for like $0.60. You know how the stereotype is that hotdogs are made from feet and assholes? Those Bar-S fuckers tasted like they actually were.
Sometimes the off brand is even better than the name brand. Oreos, for example, are way better than Hydrox.
I'm guessing this is an American thing, because branded versions of common grocery items are typically industrial, overprocessed garbage. Or maybe the OP means actively manufactured stuff like cereal or yougrt as opposed to actual common groceries like meat, cheese or vegetables? i don't know it's weird phrasing either way.
FWIW, not in the US and it's unbranded fresh/locally sourced stuff>store brand from specific stores>industrial brands for me in most cases. Except what? Olive oil, maybe? Cookies, in that locally made cookies are actually more expensive than the mass produced sugar pucks. Eh... I don't know, soft drinks and snacks? Basically if it's actively trying to kill you the big brands do it better.
Non organic and GMO foods. Oftentimes the only difference is the label. Even if truly "non GMO" that doesn't count for the thousands of years worth of selective breeding that are basically GMOs with extra steps.
Not to mention for organic and GMO food they often use a shit ton of pesticides because they can't use plants with built in insect resistance.
Another, perhaps controversial, item are non cage free/free range eggs and meat. Similar to the first point, most of these only differ in label and there is often no difference. Even if they are free range and certified by the government, the official definition for free range is a maximum of 5 chickens for a 1x1meter of space, hardly free range. Cage free is even worse, instead of many small cages it's essentially one large cage with thousands of chickens and much greater chance for workers to step on and crush them while attempting to work.
Food should be cheap but a company's soul objective is to increase revenue (high prices) and reduce cost (inhumane conditions). Even farmers markets are corrupted, many of the stands there sell goods from large producers to capitalize on peoples willingness to spend more for "local" and "humanely" produced goods.
That being said if they are genuinely a local farmer doing honest work then please support them. They need all the help they can get.