I am in full agreement on the relative pointlessness of 55s for all but a few applications. The only reason I mention the 55 and 40 is because that’s what I have on hand. I have a 75 that is currently in use, or I’d just go for that. I’m a bit hesitant to spend the money on a tank that I know I’m not planning to use for that long. And a 75 isn’t easy to accommodate space wise so I think I’d be less likely to keep that one up and running vs a 40.Also going to second 75 over 55
The 55 really doesn’t leave much room in it for rockwork and so on. The extra width of a 75 gives you much more flexibility.
IMO the standard 75g rimmed tank is a great first tank, and large enough to be many peoples last talk also. Nice water volume, lots of fish options, lots of space, but not so deep it’s difficult to access the rear/base, lots of sump options, and lots of economical equipment options.