First - I just want to thank all of you for posting your images as they brought back memories of my teen years. I miss at times not having an aquarium or two (my largest number at one time was 7 large tanks and a couple of small tanks).
My first tank was a 10 gallon, which housed 2-platy, 2 black Molly, 2 guppy, 2 swordtail and 2 Angelfish. As the Angels grew, had to get another 10 gal tank and later added to the first one some Tetras, small dwarf "catfish" and alge cleaner. Finally I ended up with multiple freshwater cichlid tanks, marine tanks and African cichlids. By far my two greatest accomplishments were breeding (at that time very uncommon) Discus, a couple of African cichlids and keeping sea horses alive for more than 3 years.
Unfortunately, where I lived then was in a quake region and though I was lucky (didn't lose all but 2 fish) several tanks were cracked or tweaked and I ended up back with one tank that I build 24"Hx20Dx60" that later was given as a gift to another upcoming lover of aquariums.
Again thanks for all the great images and nice to see people still enjoying a great hobby. Btw, not crazy about the sink tank, as hot water would not be a really good idea to run on the top of those fish (grin).