I would do a heavily planted aquarium with several Apistograma, maybe A. cakatoides? Or maybe Blue Rams? Or maybe an African rift lake? Or a Wolf Fish set-up? Or a blackwater setup? Or even a mangrove?
Am I rambling? Or are there just soooooo many possibilities?
All that to say this... As CFC said, it's up to you and your taste. Find a good LFS with a variety of fish. Get the names of the ones that you like, and choose some that are a "must." Then give us an update.
In the wide world of fish, no choice is wrong, and no setup is better. It just matters if you, and your fish are happy.
P.S. Just have fun with it.