I use Wardleys crumbles, but the goldies are sooo messy and it's always all over the tank by the time their done. Have just ordered a pack of Hikari Cichlid Staple pellets to see if they work better. The packet says their good for goldies too
I give mine:
A bunch of fruits/veggies(peas, lettuce, oranges, grape fruit, apples, mangos, romain lettuce and other veggies)
Algae Wafers
Shrimp pellets
brine shrimp(frozen, live or freeze-dried)
Bloodworms, frozen or freeze dried.
Live mosquito larvae
bio blend goldfish pellets
hikari sinking pellets
Omega one flakes
baby guppies
and some other things, but I can't remember
If a fly or mosquitoes got in the house my kids would swat it and feed it to the fish. But I stopped that because I didnt want any parasites or other stuff getting in my tank and causing problems.
But...koi and goldfish do it all day in outdoor ponds.