Earth is an amazing planet. We managed to spread over its entire surface with only Stone Age technology (which, in the event of infrastructure collapse, is likely all most of us would be able to create on our own). There are only a handful of areas that we are limited to expeditions: Antarctica, near volcanos, radioactive areas, high mountains.
The kind of planets I'm looking for are not like Earth. I'm looking for planets that, while suitable for some sort of species, would not be suitable for full-scale colonization by another species without terraforming. (To be clear: they are capable of terraforming or building dome habitats, but that is an investment.)
Obviously, each different species can adapt to different levels (penguins are just fine living where they do), so I'm not looking for values on each axis-of-needs, I'm just looking for the axes themselves.