Need ideas for a "center-piece" fish for a 37 gallon..?

A dwarf gourami would look nice :) And maybe instead a male betta....But they could kill the other fish or get their fins nipped so.......I would go with the gourami :) Hope I helped! :) I had the same problem with adding other schooling fish with my tank...So I dont blame you with not buying more. Well, Good Luck! :D