"Small Brooklyn apartment" stands out in your post. That makes it difficult.
My first thought was a Sherline or Taig machine because they are compact and can be set up with different accessorise to do different operations. I guess you have to consider what kind of work you want to do. How big? What kind of machining operations?
If you need a bigger machine, I would start with a lathe. Some milling can be done in the lathe if you buy or make some attachments. Although it is possible to make turnings in a mill, it is much more difficult and there are many more restraints that way.
As an aside, the machines I use the most are probably the 4x6 band saw and the drill press.
Make it fit.
You can't win and there is a penalty for trying!