Your best bet is to stop by a Art Store and purchase several brands, judge for yourself doing color tests.

You also need mediums for Acrylic paint, the ones that retard drying for example.

Golden. Huge range, high pigment load, great company. A little more expensive than some but worth it.

Golden OPEN is good if you like extended blending times (not as much as oils).

Liquitex Professional, Golden, M. Graham, Winsor & Newton, Matisse Derivan, Chroma Atelier, are all good. There are heavy body (like oils in consistency, buttery), and fluid (also called soft body). Not all manufacturers offer both. Look for artist or professional grade. I second the comment above about Golden’s customer service.

I have mostly Golden acrylic paint and I’m switching over to Winsor & Newton (assuming it’s as good as I’ve heard). I’ve ordered 2 W&N colors and 2 kinds of white to start with. I’m tired of how much time I have to waste because Golden and most other acrylic paints get darker when they dry, apparently because they have a white acrylic medium that becomes clear when it dries. It just wastes so much time remixing and repainting areas to try to get the right shade. And this is especially a huge problem when you are trying to make subtle changes in shading. So Winsor & Newton professional acrylic paint is made to change shade as little as possible as it dries because they use a translucent medium. It also takes longer to dry, so it’s easier to blend. I heard something similar about Old Holland so I also ordered a tube of their Indigo, wich W&N doesn’t have. Also W&N seems to have more chroma than other brands. I love bright, strong colors and I dislike dull, greyed out colors.

I use the paint brand that has the pigment I want and can be easily acquired in the area I am in.

Mattise has Prussian Blue, which I could not find in any other brand available near me.
Golden’s Green Gold is NOT PY129 therefore W&N is the brand of choice for that colour.
Golden has buff titanium that is a single pigment, therefore that is my buff titanium paint.
Liquitex is quiet nice and was cheaper than golden for the same pigment.

Now if I was to limit my self to one brand it would depenend on the circumstances.

If price is no issue: Golden or W&N or Matisse

Golden for the large amount of pigments and convinience mixes, and the multiple paint lines.
W&N for the limited amount of pigment choices (I like most of the choices they made) that include some fun and interesting hard to find pigments, quiet nice paints.
Matisse is generally cheaper but it has a couple of specialty paints that go up in price (YnMinBlue or the Mayan colours)

Medium price: Liquitex or Attelier or Matisse

Liquitex I enjoy the mediums they offer and the paints a pretty good.
Matisse for the pigment choices (thought I don’t like how many mixtures it appears to have sometimes), it has Prussian Blue.
Attelier is good enougth, seems to be lacking in some more unique and interesting pigments.

Low price: nope buy a more limited pallet of the outher brands instead

W&N is probably my favorite acrylics.

I’ve tried Golden Open because there was a bit of a hype about it a few years ago. Frankly I’m not a fan, while Golden Open dries slightly slower, it is also far more transparent than regular acrylics because they basically add retarder to it. I might as well paint with watercolor at that point.