First off, all my guys live in divided 20g's, because they love having a neighbor to interact with.
Geoffrey and Chaucer live on my bathroom counter (long counter with two sinks, the 20g long sits between them). It makes for a bit of a hassle for space, but it's worth it to have Geoff hang out and watch me brush my teeth and wash my face. He's fascinated by personal hygiene...;) Chaucer dances, and would eat until he exploded if allowed. ;)
Toulouse and Somerset live in the 20 long on the wall across from the bathroom counter. Their tank is on a narrow table I put there for them.
Buckley and Copper share their 20 long in the bathroom proper. (It's one of those bathrooms with the hallway and the sinks, then a small separate room with the toilet and the bathtub/shower.) Their tanks is in front of the small bathroom window, and I'm hoping we have some birds come back and nest in the corner again this year.
These guys all live in the bathroom for ease of tank cleaning. Now that they're all cycled, I will probably start moving them, but right now they're just where they started. Plus, the bathroom gives plenty of light for the plants, stays nice and warm, and I'm in there at least twice a day to visit when I get ready for work in the morning and then at night when I shower.
Next up is around the corner in the bonus room. This is my "catch-all room" full of odds and ends of furniture, whatever craft project I'm currently working on, and all my sewing supplies. Needless to say, I spend a *lot* of time in here, so I get to visit the boys often.
On a table against the wall is a 20 long housing Emmett and Duncan, and caddycorner (so he can still see/is abutting his neighbors) is Roslyn, who lives in his own 10 g.
They live here because there's a table to support their tanks...and it's still pretty close to the bathroom for water changes. :)
A few feet down the wall are the girls. They are all still in QT and so are well separated from everyone else. Currently there are two QT's going on, 3 small QT tanks in a larger heated 10g (so everyone has their own tank, but can see and get used to each other without possibly sharing anything); and a second QT set up with three more girls in small QT's in a larger heated Rubbermaid. Both tanks are on chairs so they're not on the floor, and are near to a window. They're pretty much there so that they can be separate from the boys during their QT period, and because there was an outlet there to plug in their heaters and their lamps. ;)
Still working out names. :)