It depends on what you want to do with your images.
For printing, you want the best possible match between the image on the monitor and the print viewed under your viewing conditions. That way you know that your editing steps will be shown truthfully in your prints. Color constancy causes that print to look good under almost all other viewing conditions. So adjust both the color temperature and the brightness of your monitor to match your prints.
For use on the internet, all bets are off, because most people don't calibrate their monitor. D65 would be a good choice.