I am reluctant to have anything in the house that uses energy 24/7. With 8,760 hours per year, small usages add up. One such is the exhaust fan on the composting toilet - at about 20W it uses 175 kWh/year, or 4-5% of our energy usage. Another is the cable modem for internet access we have from Comcast, and the Apple Airport Express wireless router. I've been measuring both. The router uses just over 3-1/2W, the modem 6-1/2W. Together they are 88 kWh/year. I imagine that if we were off-grid we'd unplug them in the winter when solar power is short. Being grid-tied, we're just lazy about it.
What's using power 24/7 in your house?