agreed above with the seven gal., the 22 gal. youll have more options, just depends on what you like...excluding pacus, oscars and other large growing fish. make sure you know max size when you buy the little guys at your lfs. if you like cichlids shell dwellers are too cool and you could do them, maybe rams or apistos. really just starting out Id go with something hardy and fairly cheap, maybe some zebra danios, cory cats and some otos to start.