I wish I had $5.00 for every time someone asked me what the best paint is.
Everyone wants the best used on their project and sometimes they are willing to pay the higher price for it too. Ha ha.
Millions of dollars are spent on advertising by companies to convince you they have the “best”.
The truth is most paint manufactures have good and not so good. Paint companies try to market to all demographics. People with money to spend and those on a budget.
One simple way to determine the quality of paint is to determine the percent of solids by volume. This information is available on a material data sheet. Not a material “safety” data sheet. If you go to a box store like Home Depot, etc. they aren’t going to know what you are asking for and you may get a strange look at even a paint store but this is valuable information to have.
The simplest way to understand this is to think of a gallon of paint. If the percent of solids is 50% then the other 50% is the solvent or water in latex products. The solvent evaporates off as the paint dries so 50% remains behind or on the surface of what you are painting. In general a product with 50% solids is going to be better then one with 40% solids. Do you want to buy a can 50% full or 40% full? The other 40 or 50% serve a purpose but go away as the paint dries/cures.
There are other considerations to consider like what the solids are, what the binder is, etc. but this is a simple way to know what you are buying.
If you buy a product from a reputable and well known brand and pick a product with high solids by volume you are likely getting a good product.
Shopping at a paint store is preferred for quality. Paint stores carry a better grade of products and the employees usually know the products they are selling.