I take the longer route to and from work during summer months riding the fixed wheel.
So it ends up being 16 miles a day plus a few extra.

Put myself down for 4-7. My commute is seven miles door-to-door one way (14 miles RT) by the most direct route. It can be 8+ if I stop by the grocery store on the way home or run other errands. Those are just bonus miles, though! :)

24 miles going in, depending on the route, 34-45 going home (traffic prohibits me from using my inbound route.)

I assumed you ment 1 way, 21 miles, not round trip of 42.

5 miles to work ~750' of climbing in the first 2 miles

5-15 on the way home (only 5 miles of asphalt:thumb:) and of course 750' of downhill goodness

Shortest distance is 19 mi o/w, up to 25 depending on which route I take. I just ramped it up a bit this year with a job 1.5 mi further than the last one, and it's a bike shop, so I ride just about every day.