My Aquarium
This is my 60-gallon aquarium.  I keep the water at a constant temperature of 82 degrees fahrenheit.  It is important to note that this is a community tank, and this temperature seems to be perfect for all my fish.
Fish in my aquarium:
2   Discus
6   Albino Barbs
3   Giant Danios
11 White skirt tetras
2   Plecos
1   Rapheal Catfish
My aquarium consists of multiple fake plants, called plantastics.  Live grass, which I also have, is recommended for aquariums with one or more discus or angelfish.  Also, I have dried rock formations, which I would recommend for black ghost knifefish and some catfish.
All tropical aquariums are going to need a filter and heater.  For my 60-gallon aquarium, I use a Magnum 350.   Another recommended brand is Penguin.  My heater is 200-watts.  Of course, the power and wattage needed for the filter and heater varies depending on the size of the tank.