Current Location: Stockholm, Sweden
It never ceases to amaze me how light can change one's view and general perception of city (or any location for that matter). When it's the night time things can look completely different to the point that their unrecognizable, bringing with it mystery and even forcing yourself to question your own memory of something (maybe even adding a bit of fear or excitement in what you're doing).
I prefer to see a destination in the daytime and at nighttime because of this wide variety of sensations (I easily can't even say that I've been able to pinpoint all the possible combinations) that can accompany the cover the darkness.
Here in Stockholm I never truly got a sense that going out at night is something that someone should, if not necessarily avoid, be wary of (indeed I've felt the same about all the European cities I've visited). I feel as though a majority of people "here" (being Europe) go out in the evening and stay out whether they are having dinner or just being with friends and/or family.
Now, I'm not saying that back in the States, day after day, people just come home and stay home. I just feel as though many would prefer not to go out (or at least I don't see a large and healthy mix of different age groups) about cities, towns, or suburbs just walking out and about.
But hey, there's always the daytime right? I guess it really comes down to even split in the middle in terms of my preference in when I would like to explore a location. In stark contrast to night time, exploring during the day can be freeing since you can, practically, see everything and, because there are more people about, you can truly get a feel for the life of the city (that and stores and sites like museums are open as well).