What's wrong with Jamis bikes that are named "Commuter"?
Aluminum frame? Less rust, a beater commuter bike usually has chipped paint.

Commuter 1 http://www.jamisbikes.com/usa/bikes/...commuter1.html
Commuter 2 http://www.jamisbikes.com/usa/bikes/...commuter2.html
Commuter 3 with Shimano Nexus http://www.jamisbikes.com/usa/bikes/...commuter3.html $550
Commuter 4, this is strange: internal hub + derailleur http://www.jamisbikes.com/usa/bikes/...commuter4.html