One of my favorite fish, and one of the oldest in my aquarium (I've him him for almost five years), is the Clown Loach
The clown loach is an active schooling fish that is best kept in small groups of three to six fish. It will tolerate tankmates of other species, although docile species may become agitated by the constant activity of this fish. The clown loach may alarm its owner by lying on its side or back — while resting — appearing to be dead. This is normal clown loach behavior. It also makes audible clicking sounds in the evening, especially when feeding.
Because it is not a territorial fish, the clown loach generally poses no threat to its tankmates. However, the clown loach may become entangled in nets. This species can live for as long as 20 years in the home aquarium.
Provide a soft substrate because the clown loach likes to nose through the substrate to find tidbits of food to munch on.
The clown loach will accept most commercially prepared flake, freeze-dried and frozen foods. Its diet should be supplemented with small live foods, such as Tubifex worms, bloodworms and brine shrimp. This fish also loves snails. If you ever took home a live plant and ended up with a snail infestation, this is the fish that will take care of the problem.