I used to use nothing but chicken livers, but there are too messy. I switched to raw shrimp or hot dogs and seem to do just fine if not better.
When the shad run is on in the Beaver & Ohio, you cant beat them, use a dip net and in a few minuets you got enough bait for the summer. Freeze them in baggies and you always have bait.  Carp I like to use bread or @ Pymantunning, I use my fly rod and a bread fly I tie.
whats the biggest cats you have caught: Here are my three by species;
 
Flathead- 33"-18lbs
channel: 28"-11lbs
bullhead: 11.5", no weight taken
no blues

Live bluegills for flatheads.
 
Blood dip bait for channels.

For cats I'll use a variety of baits.....creek chubs or suckers.....small gills.....heads of trout kept in the freezer from trout season.....Chunks of almost any fish including carp and the mighty crawler.
 
For carp.....I like to make my own doughball(vanilla, gravy master, maple) are my favorites. I make all flavors with part of the ingredients being creamed corn mixed into the recipe.
 
For finiky fish that have been caught before I like to use a "hair rig" which helps hook those fish that just seem to be tasting your bait. Several fellows that I have shown this to say they have increased their hook-up to bite ratio by 50%.

Any kind of fish for the cats, And I'll agree with the fries for carp. (Although the ones from Jerrys Curb service beats Mickydees hands down.One of my kids put one on for a joke years ago, and they are still the best carp bait I've ever used.

Carp: Dad's 'ol dough ball recipe and corn
 
Cats: Large fatheads preferrably dead.

Does anyone know how I would catch a carp on a flyrod.  Just curious to know what flies would be successful. 

cut up trout the best for cats

for cats i like beef liver soaked in caned tuna oil. stays on better than chicken liver.

ORIGINAL: gizmos

Any kind of fish for the cats, And I'll agree with the fries for carp. (Although the ones from Jerrys Curb service beats Mickydees hands down.One of my kids put one on for a joke years ago, and they are still the best carp bait I've ever used.

 
French fries? For carp, eh?  I'll try it, sounds cheap and easy.

ORIGINAL: Wally Cat

For finiky fish that have been caught before I like to use a "hair rig" which helps hook those fish that just seem to be tasting your bait. Several fellows that I have shown this to say they have increased their hook-up to bite ratio by 50%.

 
How do you rig a "hair rig"?