I always end up making the Red Rocket my home base. I don't want, or need, settlers at my home base so it's plenty big enough for me, Dogmeat, and Codsworth to hang out. Plus it has that nice flat and clean cement floor in the garage bay. Makes it nice when I drop and salvage all my junk. No hunting for small items that might get lost in the weeds or uneven ground. Just about every other settlement out there that is a major problem.

For building a town, and filling it with settlers, I like the Drive in, Abernathy Farm (biggest flaw is no standing water for purifiers), and Sanctuary Hills.

There are a few others I keep looking at but they all have a existing building that is missing most of its roof and you cant fix it with existing items in the build menu.