I used to have seven fresh water tropical tanks (a 42", a 36", 4 x 24" and a 20"). At my peak I had in excess of 100 fish, my favourite's being a red finned shark, a pair of spanner barbs and a 10" plecostamus. I also kept some goldfish in warm water too, and fed them on raw liver, which made them grow rather large (hence the large plecostamus which used to clean up after them).
Over the years, due to the expense of keeping them all warm in winter, I gradually shut the tanks down one by one until they were all gone. I do miss those nights that I used to spend long hours watching them though. Once you got to know their personalities, they were better viewing than television.