Depends ofcourse on what type of community you already have. I love my gold honey gouramis, you can also find other beautiful colored gouramis like the red flame.
Severums, Uarus, Surinam geos, badis, smaller sleeper gobies (Mogurndas or peacocks), Apistogramma, dwarf acaras, flag cichlids, pearl gouramis, ctenopoma species I could go on I am biased to fish with some level of intelligence, as you can see