I keep saying my 2 mile commute isn't worth it, but I keep doing it 1/3 days of work. Before my office moved, the commute was 2.5 miles, and I sometimes took a longer way home, to make a total of 8 miles. But, I like the nice feeling I get, it's just not long enough, and requires some planning. Before I moved, my commute was 10.2 miles round trip, which seemed perfect.
Starting in October, I will be facilitating a group for domestic violence victims on Friday mornings (right now, I don't work on Fridays). I probably will ride there, or bring my bike in the car and start/finish a ride from my office, especially when it's colder out. But still, is it worth it? I can easily drive there, drive home, and set out on a ride from home.
My favorite commute was my first one, when I was teaching. I lived 6.7 miles from my school (after figuring out some roads I never knew about) and the route there was a good uphill near the end. Going home was a breeze and it was all quiet country roads. When I moved to Concord, it was just under 14 miles, more like a ride. I did it twice a week for the last 6-8 weeks of the school year and a couple of weeks in the fall, as this was before I rode in the dark or had good lights. Twice a week at 28 miles rond trip, even a few weeks of the year, added up.