I like Spectrum Thera A because it has garlic which could be helpful to fight disease plus it seems fish like them much more them ohe dry food without garlic.
I steal a fresh shrimp from my wife once a week or so as a treat, but daily I use, Formula ONE Marine Pellet w/Garlic and Two little Fishies Sea Veggies Green Seaweed.
Just an FYI...
I had problems with ich till I started using "Formula ONE Marine Pellet w/Garlic" in my old tank. That may not be proof that it keeps fish healthy enough to fight off ich, but they like it... If it works...