I work out at home with exercise videos. Monday is the most important day; if I get in a workout Monday morning, it sets the tone for the week and I am much more likely to get in several more workouts during the week. The reverse is unfortunately true as well; no workout on Monday makes it that much harder to get going later in the week. I also try to do a tough workout on Monday, again to set the tone for the week.
Today I did a challenging full-body strength workout. I will be sore tomorrow--but I love feeling like I've done what I could to start the week off right, at least exercise-wise.