I think Townie is super interesting. On a user level, I really like that I could build this blog with it, and it just worked... It seems like a pretty complex set up, but looking at the source code it's been really interesting to see the agent, the tools and the tool loop in action and how the system prompt is applied.
I know a heap of other agents follow a similar pattern, I just found this one particularly easy to understand and worth checking out.