I shower both in the morning, and in the evening. Thus didn't vote.
As far as the hygenic debate goes; it is best to shower both times of the day, imo. At night, you're getting all of the gunk off from the day. Whereas, in the morning, believe it or not but sleeping does get one a little dirty. I don't care how often you wash your bedding, or if you don't WAKE UP sweaty, you DO sweat in your sleep, plus the morning showers are nice because they help wake you up!