J.M.
I had a night light in my DD's room from the time she was born, until she was about 20 months old. She started fighting sleep so much, that I took it out hoping that if she couldn't see so well that she wouldn't be getting up so often. It worked! :) I leave the door open, so she has a LITTLE bit of light at bedtime, then I shut the door when I leave. So she doesn't have a night light right now, and seems to sleep better for it.
I personally sleep better in pitch-black than with a night light as well...
I think it depends on your kid, what they are used to, and how they react. :)