If you truly want to feed the best, feed live foods a few times a week. Or feed frozen if live is just not possible. Microworms are very easy to culture as live food, and will be greatly appreciated by virtually all fish.
Frozen daphnia, brine shrimp or bloodworms are also eagerly taken by almost all fish, and live or frozen foods offer things man made food can never really duplicate completely.
Microworms remain alive in the tank for several days, at least four, so the cory can find them and they won't die and foul the tank. Vinegar eels are very tiny, but also can survive in the tank until eaten. Dapnia are a bit harder to keep, but fish love them and you get colour like nothing else, and they also live until they're eaten.
Fruit fly, the sort that can't actually fly, or their larvae, are also eagerly taken by most fish. A bit more work to keep fly cultures going, but if you aren't able to keep live cultures, get frozen foods for them and feed some at least twice a week.
I think you'll be pleased by the response of the fish, and they will be healthier for it.
