I chose kitchens, probably also because of all the cute clutter you can use for it. And I love making constructions with the differently shaped counters/islands and wall cabinets. Which is also the tip I'd like to give, switch auto-counters to off, so much more versatility.
I also really like making kids/teens bedrooms, if you have the right packs, you can really make those rooms fit the sim's personality.
This is the most recent kitchen I furnished, it's in a large family cabin in Granite Falls:
https://66.media.tumblr.com/54b3c73d16a999b06af4a6bb90c72e08/tumblr_pvannmLBXc1v8k7elo3_1280.jpg
