Idk I think my best built houses were created in ts4
but at the same time that is mainly because:
in ts1 i just replaced furnitures of existing house with fun gameplay objects thats all i built and anything that did not fit was put outside
in ts2 i didn't care to create anything realistic i would just make big box with disco wallpaper and put all the fave gameplay objects in
didn't matter if the rooms were ridiculously big and there was 50 toilets and you entered the house through bedroom it was full on chaotic evil at that point
ts3 i started trying to build houses somewhat more seriously (well probably cause i was bored with playing)
but i was still stuck making red gothy box house or creating most unnerving glass box i could think of cause idk. emo phase and modern architecture was real cool i suppose
ts4 is probably first time i really felt like trying to make realistic homey nice looking house and make the outsides look cute so now i dare say my builds are starting to look better (well after few years)
but i do miss my ridiculous chaotic evil houses i can't really make with ts4 anymore cause we dont have enough weird fun stuff :( and it makes me feel rather uncreative at times
