Winter: ~77-79F. The vents are blocked off elsewhere to keep the heat in the room I'm usually in. The air's nice and dry in winter, so higher temperatures are preferable and more comfortable for me.
Summer: More like 72-74F.
I don't really care for temperatures below about 68F, as my hands and feet start to get really cold, then they start to sweat, and evaporation makes them even colder. :\
</first world problems etc etc>