I would consider any type of food that doesn't really have anything with the word "filler" or "fill" in the first 5 ingredients to be a premium based food. Some people think that it is based on the brand, but sometimes you can find very common brands having fillers as the first 3 ingredients (which in fish food the order matters since that is the amount of ingredient type being added from most to least).
Some of the more commonly known premium brand foods can include Omega One, Aqueon (some of their foods, others have fillers like no other), local foods that you can find in random stores, and the best one would be those who make their own fish food online and sell to others (I think Dustin.tv has his own brand now as do many others).
STAY AWAY FROM FOODS LIKE TETRA, OR OTHER CHEAP BRANDS! You may think you are saving money at the start but you aren't allowing for your livestock to reach their full growing and life potential that they would have reached given a rich diet their whole life.