Depends on what you wanna build to be honest.
Do you wanna do easy decorations that you can change out in mere minutes, then it's the Condo and the Suite
Do you want area to build a little bigger within certain parameters then Underwater, if you wanna keep the theme of it being a home then it's Highrise.
And then if you wanna do all sorts of random stuff from small designs you can implement in your other houses to making huge projects that involves whatever springs to mind then it's Smooth Dirt you should pick.
Due to Smooth dirts enormous size you could create basically anything here, like Castle Wolfenstein.