Again, assuming that you have done the homework regarding the local regulations governing this type of collection...if it were my tank I would make a choice between a single bass or a community of smaller fish. Bass get big, and don't play well with other fish smaller than themselves. They're not particularly aggressive but they are very predatory and gluttonous. A single would make an interesting, active and interactive display; sort of the native fish equivalent of oscars, red devils, etc. but with the potential to outgrow most of those species.
If I were going the community route, I'd choose almost any species other than the bluegill (yes, the term "bluegill" refers to a single species of sunfish). Bluegills are one of the bigger sunfish, and one of the least colourful. Pumpkinseeds or others are better choices due to smaller size and much brighter colours. Sunfish in general (including bass) can be thought of much like cichlids; potentially territorial and aggressive. Rock Bass (a personal favourite) are similar, not brightly coloured but still attractive and interesting. With any sunfish, you'd have best success with either a single one, or a group of 5 or more to spread and reduce aggression.
Minnows, shiners, dace, etc. are sort of the native equivalent of tetras and barbs; smaller schooling fish, active and attractive in groups. They grow to various sizes and have varying requirements; you should try to identify the species you have and choose something appropriate to your tank size and conditions, rather than just dipping up a netful of assorted little guys and calling it good.
Crayfish are interesting. They are also predatory upon smaller fishes (especially after dark), attractive as food to larger fish like bass, quarrelsome amongst themselves, and very prone to being eaten or killed immediately after shedding their shells. They also have a tendency to mow down your aquatic plants right to the roots. They would be analogous to...well, they're not really the equivalent of anything that is commonly kept in tropical community tanks. They are essentially just a PITA; they're cool, but the only time I have had long-term success with them was when they were kept on their own, in unplanted tanks. Easy to keep, though, and interesting.
My suggestions all come from the viewpoint of someone who doesn't like crowded tanks and wants to choose livestock with an eye towards keeping the fish for life...hopefully theirs rather than mine.
If you prefer to get small fish and then periodically swap them out as they outgrow their tank (as many MFK members seem to do), please consider the fact that re-homing natives to other aquarists or LFS is much more problematic than doing so with "tropicals". Not nearly as many potential takers for this type of fish. And simply releasing them back into the wild is frowned upon, as they may have been exposed to various pathogens, parasites and diseases that are not part of the local environment and should not be introduced. Disposing of them in an "environmentally ethical" manner may be distasteful to many keepers...although the fish themselves may be quite tasty when fried up in batter...
