Nest Thermostat

Now on its third generation, the Nest Thermostat isn't the only smart thermostat around anymore — but it's still one of the best. The latest model has a screen that's higher-res and 40 percent larger than the 2nd-gen, a fact that's put to full advantage by Farsight, a feature that displays the target temperature or time in large, easily-readable type when you walk in the room. It's thinner, too, still integrates well with the company's smoke/CO2 detector and cameras, and can now sense problems with your furnace ahead of time, so you're not left with an outrageous maintenance bill, or worse, a non-functioning heater.