Cheese
Fruit -- tasteless strawberries are so disappointing
Good deli meats like high quality dry sausage, pancetta, ham, etc. Cheap deli meats are generally gross and overly salty in a bad way.
Yoghurt -- can't stand the Lidl bucket o' "Greek" yoghurt. It looks like a bucket of white paint primer and doesn't taste of anything. I tend to buy Fage.
Clinique facial exfoliating scrub -- I cheapened out recently and bought St. Ives again and it made my ingrowns worse.
Hair products like shampoo, conditioner, leave-in conditioner, etc.
Bar soap and hand soap -- I've converted to buying nice bars of soap and see it as an affordable luxury since they last so long and smell wonderful. It's like cheap aromatherapy each morning. I also love Aesop hand wash.
Mrs. Meyers Clean Day products -- hand wash, dish soap, and all purpose cleaner specifically, especially in lavender scent.
Method laundry detergent
Body butter and other moisturizers
Wine -- depends where I am. If I'm in France, a cheap bottle is still really excellent.
Shoes -- I have fallen arches and need proper support so I'm not in pain.
Post-It notes. Cheap/store brand ones just fall off the bloody wall or out your notebook after the first application. It's not worth the frustration.