If you have a larger tank, pearl gourami are beautiful and peaceful. Dwarf gouramis are always popular but males are aggresive with eachother and sometimes other fish. Gold/blue/opaline gouramis tend to be semi agressive. Honey gouramis are cute and tiny but males may fight. A male and female pair is always good. Sparkling gouramies are beautiful and moonlight gouramis are light and delicate looking. Both sparkling and moonlight are peaceful. Stay away from kissing gourami because they get too big. If you have limited space or a lot of fish, go with the smaller ones (dwarf, honey).