Dimming switches are a good one always, USB receptacles placed in bedrooms and on counters, fan timer switches for bathroom fans, occupancy sensors for different rooms, caseta and pico brand switches for wireless lighting controls, always rough in for TV and data receptacles, soffit receptacles for Christmas lights, switched outdoor lighting receptacles.

Most importantly, a receptacle that is designated for electric vehicle charging. Some places actually require this by code.

There's millions of opportunities when looking at smart home electrical systems. The only question is where to stop lol