Is there an OS X equivalent to the web debugging proxy Fiddler? I do web development on Windows for my day job, and I rely a lot on Fiddler, which is web debugging proxy.  What is an equivalent tool for OS X?
Stuff that's Free:


Burp Suite 
WiireShark
ParosProxy
NetTool
LiveHTTPHeaders
Safari WebInspector Network Tab
FireBug


Stuff that Costs:


$1.99 -  HTTPClient
$15.00 - HTTP Scoop
$50.00 - CharlesProxy