I tried Basecamp once for a side project, but I quickly found myself not using it. No particular reason. I just didn't feel like I got much value out of it.
Trac is pretty nice because it's lightweight and is tied right into my repository (if you use SVN). It seems to fit my workflow better.
I have noticed a bug tracking system works better for a one-man one-project setup. You can pretty much express everything in tickets/bugs. I am using lighthoseapp.com and its working just fine for me.
Well stated. When you are working on your side project and not being paid/accountable to others, its easy to mismanage your resource (yourself).
Does anyone use the free 1-project version of Basecamp for hobby project management?