Every new contract - first two things - find the coffee machine - disable the overhead fluorescent lights by rotating them out of their sockets. In places with union maintenance I'd have to explain to the troll twice a month that I wanted it like that.

My ideal environment ever was a server room where they put me due to lack of space - I was in heaven. F-lights all completely off, small table lamp with a 100-watt incandescent bulb across the room, all sorts of twinkly LEDs, green and red - every day was Christmas!

My boss even would turn the lights off after visiting :)