I'm a big fan of
Takashi Amano (
wiki).
You can view some of his fishtanks
here.
In the past I have kept many different types of aquatic and semi-aquatic animals:

Archerfish
(
genus Toxotes)

Red-Eared Slider (
Trachemys scripta elegans)

Firebelly Newt
(
Cynops orientalis)
In Japan, my apartment is very small. Since moving to Japan I've only been able keep one 10-gallon freshwater aquarium (which I keep half filled on the floor in case an earthquake cracks the glass) as opposed to multiple tanks as large as 40 gallons in size.
What's currently in my aquarium:

Cardinal tetra
Paracheirodon axelrodi
Ghost Shrimp
genus Palaemonetes
Moss Balls
毬藻 marimo
Philodendron
genus Philodendron