I would suggest getting tropical fish. Goldfish put put A LOT of waste so their water is harder to keep clean. I have a freshwater tropical tank and, in my I have: Angelfish( I would suggest getting a female, they tend to be less aggressive but, my male is not aggressive just bossy), swordfish( 1 male to 2-3 females MAKE SURE AND FOLLOW THE RATIO), mickey mouse platy( I have nothing but good to say about these fish I think they are a must), 3dot/blue Gourami (I like these fish, I also like the Dwarf Gourami but, they are TOO docile they will not stick up for themselves at all so, I DON'T suggest those), serpae tetra(good little fish), lyretail molly(mine is the ONLY aggressive fish that I have. It is usually more aggressive around meal time. It does really eat the other fishes fins but, it chases them and, I don't think that. I also had a black molly and, it was aggressive but, I gave it away. I would suggest staying away from the mollies, someone at a pet store will tell you it will be ok but, as far as my experience goes I will NEVER purchase another molly)
Fish that can cohabit together include goldfish, tropical fish and African Cichlids. However, take note that in deciding which species can live together, you should always consider that they should have comparable water chemistry and temperature requirements, exhibit similar behavior and occupy different swimming levels. For more details, visit http://promotions.petsmart.com/landing/fish/choosing-your-fish.shtml.
dont get goldfish they send out levels of harmful chemicals that make it hard to keep a ph in the water try to start as big as you can the bigger the better (tank not fish) it is easier to keep the water just right if you have a bigger tank if you what to know more try pets mart or email me at firstname.lastname@example.org pet mart is a good place to get in foe but they not good with trying to keep you as a customer they just what you to buy something
You can try one of the most common type of fish, the goldfish. They are sometimes pretty boring, but they do get along with each other. I suggest you don't put a piranha in the fish tank or fish bowl together. '.' Moment of silence, crickets chirp in background. L.O.L!
Please do not listen to the people who keep saying goldfish. Gold fish are very calm, however a lot of other fish will pick on them. Its hard to keep goldfish with any other breed due to PH balances and such. It would be high matinence. Get a combination of a bottom feeder, a midlevel swimmer, and one that hangs around the top of the tank. They wont bother each other then.