Empty Templates. If you install all of them, you can create a custom neighborhood with all sub-neighborhoods attached, and still have ZERO sims. The game will, of course, begin creating sims once you start playing. But with the various noregen/noredundancy hacks, you can keep the numbers low, and with default replacements/etc, the new townies/NPCs can actually be good looking.
http://www.moreawesomethanyou.com/smf/index.php/topic,4306.0.htmlIf you just want to get rid of the Pleasantview townies and NPCs (Komei, Marsha, etc) you just need the empty Pleasantview. Or do what Eleonora said.