I love our clownfish - here an extract from liveaquaria - (Nemo was an Ocellaris Clownfish
) - I would suggest a pair of Tank Bred Ocellaris Clownfish
Saltwater Aquarium Fish for Marine Aquariums: Ocellaris Clownfish, Tank Bred
Minimum Tank Size: 20 gallons
Care Level: Easy
Temperament: Peaceful
Reef Compatible: Yes
The Tank-Bred Ocellaris Clownfish has other unique advantages over wild-caught species. For one, the Tank-Bred Ocellaris Clownfish is very hardy and more accustomed to conditions found in home aquariums. Therefore, it makes a great choice for novices and seasoned aquarists alike. The Tank-Bred Ocellaris Clownfish can also be kept with a variety of other tank-bred clownfish, if introduced into the aquarium at the same time
Clownfish are ideal beginner fish, since they are easy-to-care-for, hardy, and don't require a huge aquarium to survive happily. Because wild clownfish always stay in or near anemones in a reef environment, they require very little space. They readily eat most fresh, frozen, and dried foods.
Clownfish Care: Finding Nemo...In Your Home?