Join Date: Jul 2010
Location: Outside Philadelphia, PA
Usually when something is exotic or difficult to keep, it means a lot of work, and sometimes multiple tanks.
The bottom line is that it's your tank. What I might think of as exotic might seem common or uninteresting to you. For example, some people like fancy guppies, but I was never that fond of them.
A few areas I can suggest looking in to are the various species of killifish, loaches and other bottom feeders, some of the larger tetras like congo tetras, or dwarf cichlids. You could also consider angels or discus, but would need a larger tank.
In my own tank, I keep several species of tetras and rasbora. Nothing that exotic, but the colors and movement work out well. Currently I've got rummy nose tetras, black line rasbora, black phantom tetras, and the usual assortment of catfish.