When it comes to fish foods, there are good brands and less good brands. And variety is always beneficial. Many of us here (myself included) use Omega One and New Life Spectrum brands. These two do not have fillers and binding agents like cereals, which are not very good for fish. I use the NLS flake, and the Omega One Veggie Flake; they also make a shrimp flake. The mini pellet foods by either manufacturer are also good. These are for upper water fish (like angelfish); the sinking foods (pellets, disks, tabs) are good for substrate-feeding fish like corydoras catfish, loaches, plecos, etc. The Veggie flake and Rounds should be fed to all fish whether or not primarily vegetarian as the green improves fish digestion and is good for the intestinal tract. There are Bug Bites (can't remember who makes these) that are good.
The above should be the staple, meaning the foods fed most days. Frozen (fresh frozen, not freeze dried) foods like bloodworms are fine but only once a week, not more often, as they are not that wholesome. Frozen daphnia is an excellent frozen food.
Freeze dried foods are best avoided. If you do feed them, be sure to thoroughly soak them in water before placing them in the tank. These foods are notorious for being swallowed and then inflating as they get wet in the fish, causing problems. I just avoid freeze-dried completely, as this issue does not occur with the afore-mentioned flake/pellet foods and they are healthier otherwise too.
