When I first began painting on my own, I used what was/is popular at the home improvement store, which was usually Behr. And, when I was employed at some apartment complexes, Troy Hills and Eastwyck Village, I used what the contractors used or what my supervisor bought - Glidden or Passonno paints.
With Behr, I didn't care for it's smell and how thick it was. A thick paint doesn't mean it's going to cover or hide better, unless it's a specialty coating, like elastomeric paint - but that's not what you would normally use in your home. And Glidden never seemed to hide or be durable.
I will note that, at business or commercial settings, high grade paint isn't usually purchased. What's used in "contractor" grade - good enough to get color on the walls. This is the same for roller sleeves or some brushes - they're not made to be used over and over or for long lasting ability.
I also want to note that I haven't used every paint brand out there. It's not that I don't want to try them, but, this brings me to why I use Benjamin Moore - it goes on easy and works consistently well. So, if a product is working well on a continuous basis, I'm not too inclined to try and test others.
My 3 Reasons
There are a few key factors why I like using BM paint.
Benjamin Moore Brands (quick overview)
BEN - BEN is what they call their low end premium. The paints lower would be the contractor grade paints. I rarely use the BEN brand.
Regal Select - Regal Select is what I use for most jobs and is the mid-range grade.
Aura - The Aura brand is their high-end paint. I have used this a few times and enjoyed working with it. The pigments are richer and it has it's own color collection. The paint actually covers about 10% more area, which can be a benefit.
Aura Bath & Spa - Aura Bath & Spa is formulated in a matte finish (sheen) for high humidity. I have used this and is a great option for those who don't want a glossy look on bathroom walls.
Natura - Natura is certified asthma and allergy friendly. This was the primary paint I used for the Stockbridge farmhouse. Worked great with no shortage of workability.
Advance - The Benjamin Moore Advance paint is formulated for cabinets, furniture, trim, etc. I have used this numerous times with terrific results.