I would have two main ones.
i would have a 300-500g tank with my discus. and plus what fish i have now with more room.
i would add maybe another ten discus. differnt kinds like 2 of each of all my dream discus that i prolly will never be able to get or even afford. or even more discus.
i wouldnt want it much bigger it would be to much work and would just be to big for discus.
And i would get a 300 gallon oscar tank with a few different kinds. and just uhh. (drooling over here by dreaming of my tanks)
i wouldnt mind having a room in the basement. with different tanks with different species. like maybe a small sw
with dory and nemo's. and then maybe some puffer kind of fish. and seahorses and starfish.
and then maybe some more different kinds of cichlid tanks.
i dont know i really like the cichlid species.