I do not know a large amount about saltwater fish. I went with tropical fish in my aquarium venture. I learned the hard way to stay away from the aggressive fish, most importantly Angelfish. These fish literally ate the fins off my other fish and caused them to perish.

When getting tropical fish, you need to set up a "community tank" if you are interested in having many different types. I am sure this works the same with the saltwater, so if you are venturing in that direction, you can ask the people who sell them. They are trained and know about these type.

Types of tropical fish for an aquarium that will get along well in a community tank:

Tetras: These include the silver dollar, neon, penguin fish and cardinal.
Cyprinids: These are Clown Loach, Coolie Loach, Zebra danio and Red Tailed Rasbora.
Catfish: I know it doesn't sound thrilling, but some are actually cute. Emerald cat, Glass Cat, Panda Cat and Tail-spot Cory.

This site in the source gives more that are good for community tanks and specifications on the sizes and how many for what tank size.

Since you want to maintain community fish tank, better now buy any Aggresive fish like Oscar, Jewel, and other aggressive fish like these fish who would like to stay togther,

a) Gold fish types, Carps
b) Barbs, Tetra, mollys, platy, swordfish

It's suggested by aquarium experts that you combine fish that require a similar water environment so that no fish has to live in water which is out of their natural range.

The following are some popular colorful, affordable and nonviolent freshwater fish that can live together:

• Zebra Danio

• Dwarf Gourami

• Neon tetra

• Guppies

These marine fish species can also live together:

• Clownfish (Amphiprion darkii and A. sebae)

• Blue damsels

• Smaller Labrids

• Blennies

Visit the site below to learn more about aquarium setup, choosing tropical and fresh water aquarium fish and how to maintain your aquarium.

Source: http://www.amysguidetoaquariumfish.com/