Stocking a 55 gallon fish tank

[Alphau]

In our tank we have a Jack Dempsey and Convict - but be advised they are mean old fish..

 

[Penturner]

My two favorite fish are both South American Cichlids, well one is a cross of South American cichlids. The Tiger Oscar. or the Blood Parrot.
I had a huge pair of Red Tiger Oscars in a 55 gal tank for a long time. they have great personalities, will get to know you, will eat out of your hands. and actually have different temperaments toward different people. They would eat out of my hand but splash the surface at my wife. they also learned that my wife woudl open the lid to much and leap out of the tank on her.
The Blood Parrot is by far my favorite fish. I have one that actually rubbed itself against my fingers like a cat would against your leg. they are extremely shy but their curiosity obviously contends with that. If you set still near the tank they will come close to check you out. once they get familiar with you that appear to be very much affectionate. I had a single female that laid eggs weekly on the glass of the aquarium but they are a sterile cross. Closest thing to a real pet I have ever had in a fish, and I have had lots of fish.
I really like tetra tanks with about half a dozen Bala sharks in there for some flash and size. large schools of tetras look better than a few each of lots of different ones. Bala sharks get large so you do not need nearly as many of them.