For me it really depends on the situation. When I'm gaming or watching a movie, I prefer effectively no light. In fact, I built an enclosed space in my garage that is light tight. Then I have an overhead LED strip with variable intensity control. I find that programming and video calls both work best if I have a reasonable level (about 50% of what a typical office overhead would provide). I absolutely love complete darkness but after a while I start to feel like a cave troll.