Read the label closely psycho and I think you’ll find that Miracle Whip does not use the word mayonnaise anywhere. They make a “dressing”, not a mayonnaise.
Having not looked at a bottle of it in decades, I might be wrong, but I doubt it. At least we’re on the same page about ketchup.
I stand corrected.
Mayonaise-like consistency “salad dressing” used for the same purposes for which one would generally tend to use mayonnaise-Miracle Whip.
Since I’m British, I don’t know many of the brands you’ve all mentioned. Non UK Dopers won’t know some of the ones I’m about to mention.
Ketchup has to be Heinz. I haven’t ever found another that isn’t too sweet or too vinegary.
Sliced wholemeal bread (yes, I buy sliced bread) is Today’s. Not Hovis, not store’s own, not Kingsmill, but Today’s. It tastes like real bread, and it’s delicious toasted.
Ready made curry from the chilled cabinet has to be Mumtaz. Any other ready meal is inferior.
Porridge oats are always Mornflake.
Hee hee. Nope. We have tortilla chips of all shapes & sizes, but I don’t believe I’ve ever seen any “store brand triangle shaped nacho-cheesed coated corn chips”. (Well, Tostitos may do one, but they’re another major label.)
But that does remind me of a question I’ve asked for years (dunno why I didn’t think of it before). Has anyone ever seen non-Frito’s corn chips? I’ve actually looked for these, and never found any.
I tend to prefer local or house brand chips & dips. French onion dip (the only real kind) must be the creamy kind that comes in the deep tub - not the pastewax sort in the shallow container.
National label salsas are disgusting.
Purchased guacamole is vile.
Soy sauce - forget Kikkoman’s. Hie thee to your closest Asian market and get some Thai soy sauce. MMMMMMM!!
Haven’t seen this yet, since it’s not food…
But it HAS to be real NyQuil. Store brand knocks me out for 3 hours, and I wake up even worse than before. NyQuil knocks me out for the night.
Any other medicines, store brand is ok. But not for NyQuil. 
Pretty much everything, actually - how sad is that? (But then, most 5 year olds are less picky about their food than I am.) For almost any food that I actually will eat, I can list off what brands are and are not acceptable.
But the one thing that sticks out is Tillamook Cheese. No other brand will do. I took it for granted while I was growing up - and had to go to extreme lengths to buy it when I was stuck on the east coast. Life is almost not worth living without it…
I just go with whatever I happen to like best. Some of them are store brands, some aren’t. The quality is more important to me than the label.
Having said that, there are a few brands which nothing can compare to. It has to be Coke, not Pepsi. And I always buy Heinz ketchup.
I also like Tide laundry detergent and Colgate shaving cream. We can’t get either of these in the UK, so I have them shipped over to me from the US. Nothing we have over here compares to either of those. We can get Right Gard, but it’s not the same as the stuff you get in the US, so I have that sent across the pond, too. A little bit extreme, but I’d rather have the things I like than waste my money on something I think is second-best.