I chose 70. I would prefer 68 for energy saving, but at that temperature, I sit around with a flannel shirt and two sweaters and freeze anyway. I think thermal regulation goes bad in old age. In the fall and spring I can get away with 68 because the walls aren’t so cold, but in mid-winter Montreal, I am afraid 70. We don’t have AC, BTW. A window fan in the BR always leaves it pleasant to sleep.
I can’t vote. I live in San Francisco and I keep my windows open all the time. I think it is around 62° right now. I close the windows if it rains really, really hard.
Other. I live in San Fran, and it’s off almost 100% of the time. My wife turns the heat on a few days per year. If I were single. it would be off 100% of the time.
Joe
We have a programmable thermostat. In general it’s set for 78 during the day (which is comfortable for my wife and kids) and 74 at night while we sleep. That’s in the summer, anyway.
In the winter we have it set at 68-69 during the day and 63 at night.
No AC but when my heat is on I run 60-65. I went with 68 in the poll.
I live in the state of Virginia, it’s summer and 95+ degrees, I have an big old Ruud heat pump. I have my thermostat set on 82 currently. The heat pump takes away the humidity and it’s comfortable in the house as long as I’m not doing anything strenuous. I keep the curtains/blinds closed on the sunny sides of the house.
OP didn’t specify summer/winter
Summer 76 deg when I am home
Winter 62/65 deg Night/Day when i am home.
I “might” inch the heat up to 66 deg when I am about to take a shower.
I set it at 80. I live in central NC.
I’m in the Cincinnati area, and July and especially August have been pretty damn hot this year. I set mine to 75-76 depending. Any lower than that and the downstairs is just freezing cold, and that’s where the kid’s bedrooms and my man cave are. House is a ranch with a mostly finished basement.
I live in North Georgia, and I have it set at 78F in summer. I actually live on the top floor of an ancient three story house, so it doesn’t actually ever get below 85 or so except at night or on really cloudy days. I haven’t wintered here yet, but usually I keep it on 55F. I like it really cold.
I keep it around 82 F in the summer. I live in Central California, and when you’re working out in 100 degrees, 82 feels mighty fine. I really only turn on the AC if it’s hotter than about 95.
In the winter, I keep the heater around 65 or 66, and cooler during the night. Again, too much of a change makes working outside miserable.
78 Phoenix. That’s plenty cool enough when it’s 110 or more outside.
Atlanta
74 in the daytime, 69 at night except when my wife’s away, then 73.
At 78 degrees we’re just cold enough to have to dress for it. At 80 degrees we’re mostly comfortable. Our air conditioning bills are very low ($50 or less peak per month), and our heating bills are very high ($350 or more peak per month).
During the Winter we set the thermostat to 50F while we’re out of the house, and then it’s 76 when we’re in. During the Summer we do not let it get hotter than 80F due to pets in the house and computers running.
Our thermostat is set to 78°F in the summer (Central Florida). I was surprised that the poll doesn’t go that high.
Right now at the peak heat of the summer, I set it to about 73-75 while I’m awake (depending on what I’m doing) and about 70 when I sleep. It stays at about 75 when I’m not home.
During the winter, I keep it at about 67 at all times.
Another Phoenician checking in. I’m practically reptilian (give me a nice warm rock and heat lamp and I’ll be happy):
I set it for 86 when I’m not home, turn it down to 84 when I get home, and 78 overnight when I’m sleeping (I need to be really comfortable when I sleep).
In the winter, it’s 62 overnight and when I’m not home, and I’ll bump it up as high as 70 when I don’t feel like dressing in all my clothes to sit around and watch tv. But even at 70, I’ll be dressed in multiple layers and have a blanket nearby.
We have it set around 78 on days the A/C is on. During the winter it’s 55 during the day and at night, and 62 during the evening. I’m home all day so it’s pretty chilly. Hat weather inside, for sure. I’m outside of Boston. We tried setting it higher at first this past winter (our first here) but at the $600 bill we freaked and turned it down to arctic.
For the air conditioner, I keep it set between 76-80, usually at 78.
For the furnace, I keep it set between 68-72, usually at 70.
I live in the Midwest, in Illinois.
I’m still trying to figure out the sweet spot on my AC (new place) that is the intersection between comfortable and affordable. It doesn’t seem to matter what temp I set it at, it runs every 35-40 minutes for about 10 minutes and it’s super cold. If I set it at 74 or 80 it doesn’t matter, it’s too cold and it’s running all the time. Setting at 82 means it’s too close/warm. In my old place, it was always set at 77 or so, but then I was on the second floor of a well-insulated apartment building. Now I’m in a leaky duplex built in 1928. I should be happy to have AC at all! 
I’m looking forward to winter when I can crank that sucker down and put on my Cuddle Duds and bank against my level payment to make up for this summer!