I went with ZWave, which was already widely-used in 2011 when I made that change. It has mesh networking capabilities, which means that most devices on the net act as range extenders for other more-distant devices on the same net. But I think there are a few proprietary variants of ZWave now (e.g. Zigbee).
Mine is integrated with our alarm system, and despite having changed alarm system equipment manufacturers twice in that time, these ZWave devices have worked with all three systems. It's nice, because I have all of our outside lights programmed to go on at sunset and shut off at midnight, and various decorative indoor lamps on their appropriate schedules. Even my espresso machine is plugged into a ZWave outlet, programmed to come on and start pre-heating at 5am.
We also have ZWave flood sensors and a whole-house water shutoff valve, so it will shut down water to the whole house if a washing machine ever blows a hose or if our 3rd floor water heater ever springs a leak. And since the alarm system controls it all, it will also turn on all our outside lights if there's ever a break-in attempt in the middle of the night.
That said, I'm not sure if there's a new standard out there that's even better or gaining wider acceptance, as ZWave is at least 20 years old now.