It depends on activities and social life and laundry. It may be necessary to be "freshest" when working. Others may need to "re-fresh" most right after work. Showering before going to be saves sheets. Value of water and heating water are also influences. It's sometimes a delightful luxury to shower often.
I may be a little wierd. I like my shower in the morning, it's a must for me. Then if I get dirty working or something another shower, and yeah if I am not sleepy sometimes a shower or a bath to relax.
I think it is best to shower at night before you go to bed. That way your sheets stay cleaner longer. Also it is relaxing to be clean and fresh. Lots of people say to shower in the morning to help wake up, but you can get that effect by washing your face with warm and cold washcloth.