I find that my dreams are the most vivid when I wake up in the middle of the night. They also tend to be the ones that unexpectedly mess with me during the day. I will suddenly catch a glimpse of some sight, sound, or smell that takes me back to the dream, not enough to remember it, but enough to shake my sense of reality. Not to say that my reality doesn't feel a little dreamlike at the moment anyway ...
The best thing about those 3am dreams is that it means I still have a few hours sleep left. I don't fear dreams ever since my mother taught me how to banish them by calling on Jesus' protection. It may sound a bit childish, especially for a man in his forties, but it works (as long as I recognize that it's a dream).
Still, I would prefer pleasant dreams.