What's the best fish food?

[Dewit2it]

I'm wondering what works best for getting feeding frenzies going in most lakes.  Way back when, I used to use string cheese on the bluegills at Redgranite, but I never did think it was good for them.  I have been trying koi food, but with mixed results.  The rock bass seem to like it, but the bluegills just spit it out.  When I tried cheese up on the Fleetwing, the fish ignored it and swam away.

I'm thinking about trying brine shrimp, but don't really care for the $15/lb price tag.  I'm also thinking of salting the koi food, as freshwater fish are constantly trying to keep the salt in their bodies.  That might work as a good attractant.

Any ideas?