Nest Learning Thermostat - 3rd Generation, Copper is great
I love the Nest Learning Thermostat - 3rd Generation, Copper - T3021US for it's extremely easy to install, set up, and control your houses temp by either the thermostat itself (Which I don't do as much for the app is with you on your phone or better yet saying Hey Google to my Google Home devices to adjust and control it) to having it look great hanging on the wall! It should get even better as it learns when I'm home and away and the temperatures I like. It'll be interesting to see if my bill decreases over the previous Honeywell programmable thermostat I had. Monoprice had it a the lowest price I found from a reputable website.
I have an older hone but somewhat newer furnace. Just power it off at the breaker and follow the instructions using the nest app. I had it installed and set up in about 30 to 45 min. I am a big tech guy but not much of a handy man. It was simple to do.