Hey everyone,
I'm new to this site. I am a college student and I live in a house with a few other guys. We (I) recently invested in a 55gal tank that currently houses some trpoical fish. Tbh, being college guys, cute little tropical fish aren't really what we're looking for

. We've talked a bit about maybe getting different types of fish later in the game. I personally think oscars are awesome, and, since it's my tank, I have the final decision on what goes in. So, in short, I'm hoping to get an oscar soon, either once I get another tank to put the tropical fish in, or once they die (hopefully the former). Onto my question.
As I stated, I have a 55gal tank. I have good filtration and everything. I realize I'll only be able to have one oscar, but I'm confused as to what other fist, and how many, would be good additions to the tank. Any help anyone can give would be great

.
Thanks