Um, I don't really know where to start.
Fish stuff has pretty much taken over the ground floor of the house. Luckily the house layout kind of lends itself to this sort of chaos, with everything on the ground floor (including what I call the "fish bathroom", unless I have guests staying), with just my bedroom and en-suite upstairs. Things are in a bit of a mess at the moment as I have had guests, who went home yesterday, and I'm in the process of going through loads of old stuff to see what I can get rid of.
So, going room by room, the chaos is as follows:-
living/dining room - 12 fish tanks (including 2 temporary/quarantine tanks on the dining table, and a breeding tank for pest snails on the windowsill). The only cabinet that has any room for storage is the dwarf puffer tank, where I store medication, water test kits, and several racks of test tubes.
Kitchen - 5 x 10 litre clean water containers on top of fridge, plus a few smaller water containers. One small wall cupboard by the sink containing water treatment, plant ferts, liquid carbon, and fish food. Small floor cupboard by sink contains random plastic jugs, tupperware, colander & sieve.
Spare bedroom - 2 empty fish tanks
Hallway/space under stairs - A tank. Way too many stack boxes containing previously used sand, pebbles, rocks, decor, a larger (>50L) stack box currently used for soaking wood. Large stack box for old filters, lights, heaters, etc. which I am slowly working through to see what still works. 5 x 10L containers for waste water, many buckets, and a large stack box containing maintenance items such as syphons, glass cleaning tools, aquascaping tools, tubing, etc. Then another container for towels, and the long tube I use for attaching to the FX filters to water the garden when doing water changes on the large tanks.
*coughs* I think that covers everything.