My biggest is my 55, which currently has cories, tetras, a clown pleco, and my red tail shark (which is surprisingly chill. I was worried I might have to rehome her but she does he own thing and only occasionally chases). I also have a 29g for my betta sorority, a 5g hex and a 5.5g for my two males, and a 13g that is currently empty and was going to house a rescued telescope goldfish from my boyfriend's parents' pond (it's doing really poorly with the koi and rocks... it may be fully blind from eye damage at this point and I suspect a swim bladder issue from how it was swimming), but recently mom said she's only feeding two tanks when I'm up at school (my betta boys go with me) so I'm going to have to convince her to feed the goldfish as well before I take it.
Mom has made it clear I am not to put up any more tanks until I move out though (which is unfortunate because I want more male bettas xD). We just don't have the room with three large parrot cages as well, but I'd love to have a 125 or something larger when I get my own place. I'm hoping to look into putting aquariums into the wall of a fish room (similar to how pet stores have them set up, but with some larger tanks on separate filtration systems) so floor space won't be as much of an issue.