Price: $250 (per unit) 

As we pointed out in our 100 Best Gadgets of the Complex Decade feature, thermostats play a pivotal role in our monthly expenses. Nest comes to the rescue with its smart thermal regulator, creating a schedule best suited for owners needs when indoors, sleeping, or outside the crib. Energy-centric features like Auto-Away and Energy History only add to the Nest's awesomeness. No sweat.