I consider Zerex to be a trusted brand, so of those three, I would personally use Zerex. It is easily available at parts stores and big box stores across the country.
It's my understanding that Pentosin doesn't make anything, but instead has other manufacturers put their product in Pentosin branded containers. They do show their products to meet appropriate specifications. I've used their products before with good results. But they are not my first choice.
Fuchs makes good products and is well respected in Europe. They are a direct supplier to a lot of European car manufacturers. Fuchs has never established a big retail presence in the U.S., so you are most likely only going to get Fuchs by mail order, from places like Autohauz AZ, FCP, or Pelican. And you are going to pay a premium for Fuchs.